# SMC LiPo Info



## Danny-SMC

As a proud supporter and sponsor of HobbyTalk I’m pleased to start this new thread to provide important info regarding LiPo packs for RC use. My goal is to help the consumer better understand Lipos.

In the past 5 years Lipos have become the power of choice in RC surface vehicles. In this 5 year period I’ve noticed the C rate and milliamp hour claims increasing at a rapid pace. I was lead to believe that these higher C rates were true as I believed the data supplied by the Lipo factories. Recently I found a meter that can measure the Internal Resistance of each cell within a Lipo pack. While communicating with the designer/builder of this meter and getting some measurements on various packs I quickly found out that C rate claims are mostly false. That being said it’s hard to accuse factories or resellers of claiming false C rates as there is no official standard for C rate testing.

Since there is no official C rate testing standard this opens up the door for factories/resellers to come up with a claimed C rate using different testing method or simply invent the C rate they feel will help sell the most packs and make the most profit. Now that I have my own equipment to test for C rate I will come up with my own C rate testing standard and will use this to rate all future packs we release. The Internal Resistance will also be listed on the new models so the customer will know which packs have the best performance based on the IR rating. The IR meter will be on sale on our website so customers who want to be able to test their packs and make sure they have the proper IR will be able to do so. This will show how misleading C rate claims have become. C rate and IR are directly related as C rate is the ability of a cell to withstand a certain amp load. Amps equals voltage divided by resistance.

Hope everyone will like the info I will be providing in this thread.


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## Benracin'

What about ratings for milliamps? I purchased one of your 6100mah one cell packs about a month ago and when cycling the pack all it will take is between 5600-5700 mah. That's what your 5600mah packs were taking. I used it one weekend and the numbers were worse than a pack I bought back in Oct. last year.


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## Danny-SMC

The typical range for mAh is 5% of what is claimed. It's impossible to have every cell be at the same mAh within every batch. The 6100s have been in the 5900 to 6100 range under discharge with a 4.22v charge.


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## PRI_rc

Good to see you taking on the task of a grading process for lipos. We been needing one!


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## Danny-SMC

Yes and I'm not sure if it will help or hurt SMC but I feel it needs to be done as way to many companies/factories are taking advantage of the lack of standard for C rate so I'm willing to be the one to start a standard. 

I've had success in the past as I'm the one who pushed CE to come up with Actual IR instead of Relative IR. The first few months I was accused of trying to sell lower sub-c cells with the Actual IR but in the end everyone switched to it as they found out it was the accurate way to measure the cells IR.

I hope I can do the same with LiPo cells/packs as I don't believe in the C rate of the month labels and feel it needs to stop.

Hope I can pull this off and I'm ready for this new challenge.


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## Danny-SMC

*SMC C Rate Standard*

Here is the standard that I have come up with to rate cells/packs. 

All C rate testing will be done on the cells used to make a pack. For 2S2P packs testing will be done on a 1S1P cell. This allows me to be able to do higher rate discharges and keep the Watt Hour down so my testing loads don't need to support as much Watt Hour.

When taking a 1S1P cell and adding it to another cell in parallel to make a 2S2P cell the IR drops in half this means the cell will be able to withstand double the amp load if testing were to be done as 2S2P.

Cell temperature and ambient temperature is critical to get consistent and accurate results. In my testing an increase of 3 degrees Celsius resulted in a drop of 0.20milliohms. 

The charge rate is also very important as this will have an impact on the cell temperature. 

All cells will be tested at 22 degrees Celsius and will be charged at 2C.

For a cell to be claimed at a certain C rate it will need to be able to handle the full C rate discharge and have a linear drop in the voltage curve. This means the voltage can drop but not rise again due to excessive heat in the cell lowering the IR thus increasing the voltage.

You can see the first graph of a 3250mAh cell used in a 2S Hardcase pack. Using my standard this cell is very close to a 30C cell but there is a bit of drop in the voltage then rise. This cell is most likely a 25 to 28C cell. You can see that it can handle 40C but has a major drop in voltage then as it gets hot due to the excessive stress the voltage rises again. The capacity retention is only 70% at 40C. 

The second graph is another 3250mAh at 25C. This is the graph of the cell tested in the video below.

Typically factories will claim C rate based on the capacity retention. I feel this is not an accurate method as I have seen cells stay above 90% but have the sag due to the amp load being to high.

As my testing is a work in progress I hope to post my results of each cell I test and also post the cells Internal Resistance value as once we know the IR value of a cell we can know it's C rate base on my standard. 

This should help clean up the market and I hope factories and resellers will adopt my standard but I think this will be a big challenge as many know that C rates help sell packs.

Here is a video showing how I do C rate testing.

http://www.youtube.com/watch?v=rqdLCV2goCI&feature=youtu.be


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## PRI_rc

I hear what your saying.... It won't hurt you in the long run. Smc's reputation will only get better!


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## Danny-SMC

I'm doing this new system as I don't want to be part of the C rate of the month club. 

Based on the extensive testing I've been doing recently I've come to the conclusion that 30 to 35C is the highest possible C rate using my standard. I think the factories felt pressure to outdo the competition so they decided to increase the claimed C rates then you through in the resellers trying to have an edge and they increase the claims from the factory. This means we now have 60 to 75C rated cells/packs.

In one of my tests I purchased a 65C pack and to my surprise it failed at 20C using my standard. Based on my standard it would be a 15 to 17C. I wasn't surprised that it was not a 65C as I had already figured out that 35C was pretty much the max using my standard but I would of expected it to be around 25C. 

I have allot of info to pass on and I hope this will be welcomed by the majority.


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## EAMotorsports

SMC has always been a leader in battery technology so this doesn't come as a surprise to me. Glad to see someone taking the time and spending the money to figure out a way to fully test and sell quality and high performance lipo's. 

EA


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## WIGMAN

Danny just curious if you have tested any of those 90C packs that are out there and what you came up with if you did.
Great thread by the way, glad they made it a sticky.


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## Danny-SMC

I haven't but I can guarantee they will not be any better than 35C using my standard. 

There simply is a maximum amount of amps a cell made to fit a ROAR legal case can provide. Another thing to note is mAh and C rate have an impact on each other. Typically to get higher mAh you need to lower the C rate. 

My goal is to be able to come up with IR readings using the IR meter that will give the C rate of a cell just by testing them on the IR meter. 

At this time I can tell you that a 6000 cell at 30-35C has 1.5mOhms on the meter at the end of a 2C charge. To get the C rate to be 60C I believe the IR would need to be around 0.5mOhms or possibly lower which really isn't possible.


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## Danny-SMC

*Cycle Life Testing*

Testing a cell/pack consists of C rate testing and Cycle life testing. This post is about the Cycle life testing that I use to determine how a pack will hold up throughout it's cycle life.

The packs we offer are built using the best materials that mainly come from Japan. This makes for a higher priced pack but will result in a pack that holds up better over it's cycle life.

The factory which we buy from has always told me that if they were to make cells using all Chinese materials that the packs would be cheaper but wouldn't hold up as well and to test this I should do some cycle life testing.

A few months ago I purchased some of the cheaper packs in the market to do some cycle life testing to see how these packs compare to what we offer. My goal is to try and figure out if a cheaper pack is worth purchasing based on the performance and cycle life.

I purchased a 5000/40C and a 5300/30C from one of the cheaper companies who sell online and have a decent reputation. I paid 36.00 for the 5000/40C and 33.00 for the 5300/30C. 

My cycle life testing consists of doing back to back cycling on my GFX using a 12 amp charge and 35 amp discharge with a 10 minute delay in between the cycles. This allows me to do 15 to 18 cycles a day if I plan on staying home all day. This is very time consuming but very important to show how different formulations react over a certain amount of cycles. This is harsher then using a pack under normal use but since every pack is cycled using the same method the results will show how different packs will react.

I messed up with these two packs as I didn't graph the first cycle so this will not show the drop in voltage due to the drop in mAh. On all future tests I'm making sure to graph the first cycle then the last cycle. On these 2 packs I did 24 cycles and I was truly surprised at the results compared to what one of our packs did after 24 cycles. 

5000/40C cycle 1: 5279mAh Cycle 24: 4608mAh 13.7% drop in mAh

5300/30C cycle 1: 5094mAh Cycle 24: 4618mAh 9.4% drop in mAh

SMC 5400 cycle 1: 5483mAh Cycle 24: 5425mAh 1.1% drop in mAh


I will do another 26 cycles on each pack to see what will happen but it does take allot of time to do cycle life testing and at this time I'm testing many different packs so results will only be available later on.

I do have results of a so called 6000/65C pack I purchased for 39.95 from Hong Kong. This is the pack I tested for C rate and was very surprised to see it was a 15 to 20C at best using my C rate testing standard. 

Below is the graph of this pack after 25 cycles.

Cycle 1: 5774mAh Cycle 25: 5608mAh 2.9% drop in mAh

This pack expanded some over the course of the 25 cycles. 

As you can see different packs will react differently to being cycled.

I'm not sure that we can claim that the SMC 5400 will have 10 times the cycle life of the 5000 and 5300 pack and 2 times the cycle life of the 6000/65C pack but I think this does show that our pack will hold up better over it's cycle life and will have a higher cycle life. 

I will do another 25 cycle on each packs to see how the mAh will react over the next 25 cycles.

Hope this info is helpful.


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## Danny-SMC

*ESR Meter*

We've added the Internal Resistance meter to our website. 

The ESR meter is designed to test the IR of a pack and the IR of each cell within a pack. 

To do accurate tests I've found that it's best to discharge a pack let it cool down for a few hours then fully charge it using the same amp rate for all packs. I personally use 12 amps. Pack temp and room temp is very important if your looking to get accurate results from different packs. In my testing I've noticed a change of 0.20mOhms from 22 to 25 degrees Celsius.

You can get the packs IR when the pack has some storage charge in it but this will only give you a rough idea of the packs true IR. The IR goes up a bit when the pack is stored for awhile and different formulations react differently to the charge. I suspect this is due to the heat build up while charging. This is why I recommend that the IR be measured immediately at the end of a full charge using the same charge rate for each pack.

The 2S-6S meter is selling for 84.95 and the 1S-6S meter is selling for 94.95 and it comes with a small pack ready to power the meter when testing 1S packs.


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## WIGMAN

Do you charge at 12 amps for racing too? I have a Hi-tec charger but it only goes to 6 amps, If you do is that for oval racing or off-road?


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## Danny-SMC

Higher charge rates will only improve performance if you run the pack as soon as it's off the charger as this will result in slightly higher cell temps which reduces the IR. 

Hard to say the exact impact on lap times but warmer cells will have lower IR.


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## ta_man

Danny-SMC said:


> Higher charge rates will only improve performance if you run the pack as soon as it's off the charger as this will result in slightly higher cell temps which reduces the IR.
> 
> Hard to say the exact impact on lap times but warmer cells will have lower IR.


Sounds like that means unless you know within a few minutes when your race will start and exactly how long it takes to charge the pack, the only advantage from 2C charging is the time savings, right? Since you can't re-peak a LiPo like a NiMH to get it warm again...


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## Danny-SMC

Yes you are correct. You could charge a pack at 1C and then put under some lights or other heating source and get the same results as charging at higher rates depending on how hot your heat source is getting the pack. This is why I believe teching for the voltage of the pack and temp of the pack is very important as it keeps it things equal and fair and is less hassle as heating up packs is an extra step that is useless if everyone is doing it.

It also needs to be noted that the drop in IR will impact the performance but by how much is not really known and I think it's dependent on the type of racing. In Oval this will most likely have a bigger impact than in other types of racing.

My testing using the ESR IR meter has shown that 0.4mOhms equals to 0.02 change in average voltage. When testing the IR of a cell in pack that is sitting at 22 degrees Celsius with 3.85V storage the IR will drop by 0.45 to 0.55mOhms when charging the pack at 12 amps and measuring the IR as soon as the packs is done charging.


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## Jake S

nice to see someone trying to get a more stable rating system, instead of the discharge for 5 seconds at 100% charge method.

that being said smc lipos are the best i have used in recent years, even at 3.8v/cell let another driver take my car out and was still quading a section most just rolled.

the power in these packs is just insane, if other company's are saying 60c, these are definately 70c/75c lol


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## Danny-SMC

It's my goal to come out with a C rate standard that hopefully will become the standard of choice as this will keep the consumers from being taken advantage of. 

The great thing is the ESR/IR meter can give you a very good indication of a packs C rate and performance and is not very expensive for the info it will give you.

The important things to consider when purchasing a pack should be the performance and cycle life. So far my cycle life testing has shown that some packs may have great performance on the first cycles but drop off real fast. 

All future packs we release will have all the detailed test results shown and the actual C rate graphs for the cells used in the particular model.


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## Danny-SMC

*Cell IR testing*

When I woke up this morning I needed to continue cycle life testing on a pack. I decided to measure the IR of the cells prior to the charge and with the cells discharged. Typically cells that are discharged have higher IR than cells at storage charge. As soon as the 12amp charge ended I measured the IR of the cells so this will show the difference between a discharged cell and a fully charged cell at the end of charge when the chemicals are active.

The results are pretty interesting as I did 3 different packs from different factories and this shows how different differently some cells react to charging.

The IR readings are in milli ohms and the two cells in a 2S pack are measured.

5800/25C: 5.52 - 6.04 end of charge 2.72 - 3.12 Drop of 2.8 - 2.92

SMC 6000/28C: 3.68 - 3.52 end of charge 1.76 - 1.84 Drop of 1.92 - 1.68

6000/65C: 5.00 - 5.00 end of charge 3.80 - 3.48 Drop of 1.20 - 1.52

I had a theory that higher IR cells would drop more under charge because the higher IR would create more heat while charging thus lowering the IR but this test shows my theory is wrong. The 6500/60C which has higher IR than the 6000/28C has less of a drop in IR at the end of charge. I guess the IR change when charging is related to the way the formulation reacts.

The packs are now sitting with a full charge and I will measure the IR tomorrow to see how the IR bounces back.


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## Metal

As you know, in oval single cell racing we pay close attention to how long a pack can hold 4v. IMO this directly relates to the "usable" portion of the pack. Having a pack with low ir/higher c rate doesn't always mean the pack will have the best 4v numbers. Your thoughts?


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## Danny-SMC

*ESR meter tips.*

When using the IR meter you can check the IR of the pack if you don't hook up the small pins to the balance connector. This is referred to pack mode. This will give you the IR from the pack which includes the solder connections and connector. The resolution in pack mode is 0.30mOhms. 

Picture 1 shows a pack connected this way. This particular pack has 7.5mOhms.

When you hook up the pack to the meter and then hook up the small pins to the balance connector you will get the IR of the cells. The resolution of the meter in this mode is 0.04mOhms. This is a true Kelvin connection so this is the true resistance of the cell and doesn't factor in the wires or connector.

Picture 2 shows a pack connected to measure the IR of the cells. The cells are at 1.80 - 1.80. This is a total of 3.6mOhms for the two cells. This means the wire from the meter to the pack including the Deans connector adds 3.9mOhms which is a bit more than the total of the cells. 

This shows that wire length/size and good connectors are important.

When testing 1S packs you will need to have a Deans to 4mm male connector. In pack mode testing this will give you the IR of the pack through the wire and 2 sets of connector. You can take a JST-XH female connector and remove the one of the outer wires and solder the wires on the 4mm male connector. This will give you the resistance at the 4mm male connector and will allow you to use the small pins so you will get 0.04mOhm resolution instead of 0.30mOhm resolution in pack mode.

You can see this in the pictures attached.


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## Danny-SMC

Metal said:


> As you know, in oval single cell racing we pay close attention to how long a pack can hold 4v. IMO this directly relates to the "usable" portion of the pack. Having a pack with low ir/higher c rate doesn't always mean the pack will have the best 4v numbers. Your thoughts?


In my testing it seems that the cell formulation and IR has an impact on the upfront voltage. I will try and dig up some graphs to try and explain this better so stay tuned.


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## Danny-SMC

A few months ago I received some sample packs and cells from a different factory. On the meter and GFX the IR was good when I tested the best cell in the 2S pack.

I decided to test a cell from a 6500 sample pack I have from our current supplier. The IR on the GFX was pretty much the same as the sample pack from the other factory and average voltage was the same. The only difference is the mAh which is higher on the SMC style cell. I know this can impact the voltage curve but I didn't have access to a cell with the same mAh but my findings are still interesting.

GFX data:

Sample cell: 5826mAh - 3.74avgV - 1.8IR ESR meter data: 2.04

SMC sample: 6562mAh - 3.74avgV - 1.9IR ESR meter data: 2.48

When I graphed these 2 cells it really made me wonder why the IR on the GFX was pretty much the same but why was it higher on the ESR meter. This was when I first stated using the meter and I asked the designer of the meter and he told me I should build a parallel adapter and measure the IR with the meter while the pack was charging and discharging to see how it was being affected.

I soldered a second balance tap and power leads with Deans and decided to take down the IR of the cell at the end of the charge and while it was discharging.

To compare the results I got I will call the sample cell SAM and he SMC sample will be called SMC.

IR at end of charge: SAM: 1.92 SMC: 1.92 This shows that the formulation in the SMC cell seems more active to charging.

I measured the IR at different intervals throughout the discharge.

75sec SAM: 1.64 SMC: 1.72

150sec SAM: 1.52 SMC: 1.56

225sec SAM: 1.44 SMC: 1.56

300sec SAM: 1.36 SMC: 1.48

375sec SAM: 1.28 SMC: 1.44

450sec SAM: 1.24 SMC: 1.40

525sec SAM: 1.20 SMC: 1.32


Seems like the sample cell has is more active under discharge and the IR drops more which is why the voltage curve difference gets closer. To do a more accurate test I would need to have a 5800/SMC cell but I don't have one. I still think that the formulation combined with the IR/C rate has an impact on the upfront voltage. I think there needs to be a combination of mAh and IR to make the best possible 1S race cell.


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## guver

Metal said:


> As you know, in oval single cell racing we pay close attention to how long a pack can hold 4v. IMO this directly relates to the "usable" portion of the pack. Having a pack with low ir/higher c rate doesn't always mean the pack will have the best 4v numbers. Your thoughts?


Ultimately this voltage is what we care about all else being equal. Some may find other things more important though. I always thought that lower IR and thus higher "C" would carry the highest voltage under a given load. I no longer believe this to be necessarily true.

I also believed that when comparing 2 like packs that the highest voltage packs (at a given load) would be the coolest pack thus when one pack is at it's max temp the "cooler" pack had more current capability to go. I no longer think this is necessarily true either.


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## Danny-SMC

Actually voltage equals RPM and IR equals torque. The lower IR will be more important if the cell/pack gets used closer to it's maximum rating which is very rare in RC car racing.

The only true way to compare cells/packs is by graphing them at an amp rate you feel represents the type of racing you do. Average voltage can really be misleading due to how the cells react under discharge due to how active the materials become and how hot the cell gets. The graph I posted in my last post shows how the gap closes on the sample cell as the IR drops more under discharge. In racing applications I feel the voltage in the first part of the curve is what is ideal.


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## caalvord

Good stuff keep it coming, I also like how you are not calling out the other companies. If we were gambling I would fold cause I think your holding a ACE lol.....


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## Danny-SMC

It's not my goal to call out others. My goal is to come up with a standard that will show a packs performance and C rate and hopefully clean up the BS that is in the Lipo market. Bottom line it will be up to the customers/racers to make this work as if SMC packs with the new rating system become popular other companies will have to adapt to what were doing. 

I think a manufacturer or reseller can sell high end packs like we have been selling and not have to come up with crazy claims and marketing. In the sub-c days if you matched and zapped the cells well racers would know the performance of a pack based on the numbers on the stickers of the cells. Now we have to believe in C rate claims which seem to have gotten out of control. By using IR as part of the packs rating then racers/customers will know that pack A has more power than pack B and will explain why one costs more than the other. 

I'm up for the challenge as I don't want to have to release 175C labels to sell 130.00 dollar packs. LOL


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## caalvord

Keep up the good work


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## Danny-SMC

Thanks for the encouragement as all my testing and trying to change the market can only work if people care.

I will have some more interesting testing results to show early next week. I'm going to take it easy for a few days as testing requires allot of time and I need a break.

To show how bad the market has become we were selling a 6500/40C/2S pack and it wasn't selling very well at 69.95 but I know for a fact that 3 other companies are selling the exact same pack rated at 6500/65C with a price tag of of 109.95 to 139.99. This is one of the reasons why we need a standard C rate testing method with an IR rating that can easily be verified. Using my C rate standard with no sag in the voltage curve this pack is 30C at the very best and at 30C it's very close to sagging. The sad thing is that if I were to put a 6500/70C sticker on this pack and sell it for 69.95 I bet I would sell allot of them.


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## Jake S

Danny-SMC said:


> The sad thing is that if I were to put a 6500/70C sticker on this pack and sell it for 69.95 I bet I would sell allot of them.


and that is why smc has such a good rep in the battery market, because you dont put out inflated numbers

its nice to know you have a product you can trust when you buy an smc product, and danny is one heck of a guy, he even called around to those he supplies packs to when i was looking for a 5400/50c for my indoor cars when he was out of stock.


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## Danny-SMC

Actually we do sell packs with inflated numbers as I trusted the data that was provided to me by the factory. When your honest you tend to believe others are honest as well. Since there is no actual real C rate standard I could claim our packs have the proper C rate based on my testing method just like some claim 90C and 150C using a different method. This is why it's very important to have a standard to measure C rate that everyone can follow. I realize that this will probably never happen so I decided to use my own standard on all future packs we release and also use the IR reading from the ESR/IR meter as IR is directly related to C rate. This way packs can be easily compared and will help stop the outrageous claims.

Using my standard with no sag in the voltage curve under full C rate discharge I have come to the conclusion that in a hardcase 2S pack the maximum C rate possible is 35 to 40C if the pack has 5000mAh. If the pack has 6500mAh it will have 25 to 30C. The mAh and C rate of cell work against each other if the cell remains at the same surface area. To increase mAh and keep the same C rate the cell must be bigger. This is why we have size limits on packs for racing as this keeps things under control.


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## Jake S

Danny-SMC said:


> Actually we do sell packs with inflated numbers as I trusted the data that was provided to me by the factory.


in comparison to other companies packs, your 50c pack feels leaps and bounds above other companies 50c or even 60c packs i have ran.


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## Roadsplat

Always had good performance from your 28C 6000 Mah packs :thumbsup:

Great thread. Very interesting


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## OvalTrucker

Roadsplat said:


> Always had good performance from your 28C 6000 Mah packs :thumbsup:
> 
> Great thread. Very interesting


+1:thumbsup:


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## race71

Ya I wish this was up last weekend so I didnt wast my money just because its what every one else has. lol, Live and learn always works too.


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## guver

Danny-SMC said:


> Actually we do sell packs with inflated numbers as I trusted the data that was provided to me by the factory. When your honest you tend to believe others are honest as well. Since there is no actual real C rate standard I could claim our packs have the proper C rate based on my testing method just like some claim 90C and 150C using a different method. This is why it's very important to have a standard to measure C rate that everyone can follow. I realize that this will probably never happen so I decided to use my own standard on all future packs we release and also use the IR reading from the ESR/IR meter as IR is directly related to C rate. This way packs can be easily compared and will help stop the outrageous claims.
> 
> Using my standard with no sag in the voltage curve under full C rate discharge I have come to the conclusion that in a hardcase 2S pack the maximum C rate possible is 35 to 40C if the pack has 5000mAh. If the pack has 6500mAh it will have 25 to 30C. The mAh and C rate of cell work against each other if the cell remains at the same surface area. To increase mAh and keep the same C rate the cell must be bigger. This is why we have size limits on packs for racing as this keeps things under control.


My limited testing causes me to agree with this maximum "C" in the various sized capacities. The larger packs are having a harder time making the higher "C" ratings. I can buy some actual 40C tiny packs I think , but I can't find any actual 40 C large packs.

There's lots learn and a long way to go with lipos , and I applaud your effort and appreciate the time you spend testing and sharing.

I'm not quite sure what you mean by the capacity and "C" rating working against each other. Are you saying this is true when the SIZE is limited? OK maybe I do get it, (surface area) 

I also have some problems with the cell tabs width and thickness being a bit too small and heating up. This is one of the first things to limit in the packs I have tested. The tabs in my opinion are getting too hot even before the cells do. Have you found this to be true?


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## Danny-SMC

Basically it's hard to increase the mAh and keep the C rate the same if you have to use the same size cell which is the case with hardcase packs. 

A factory who is sending me some samples sent me some graphs of a 2200mAh and 2600mAh cell and they claim it's 45C. The 2200 cell is 8x34x96 and the 2600 is 6x42x126. The 2200s surface area equals 26112 and the 2600s is 31752. To be able to get an extra 400mAh and retain the same C rate the cell needs to be 18% bigger.

The cells we use have the largest possible tabs which are 15mm in width.


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## ta_man

Danny-SMC said:


> Using my standard with no sag in the voltage curve under full C rate discharge I have come to the conclusion that in a hardcase 2S pack the maximum C rate possible is 35 to 40C if the pack has 5000mAh.


You mentioned charging the packs at 2C and that this warms them up.

Very few RC racers can, or choose to, charge packs that fast and time the end of the charge cycle to the _instant before they run_ (Oval racers may do that, but they are very few compared to the rest of the RC world).

The more typical scenario is that, no matter how fast the pack is charged, it ends up at ambient temperature when run.

Would you have a different result in terms of max C rating (with your criteria of no sag) if the discharge test was run with the pack starting out at ambient temperature? Or lets say a controlled temperature typical of ambient - the 22C you started with)? Having the packs warmer than ambient at the start means lower IR at the start thus less of the internal heating that leads to the sag in the voltage curve.

In other words: would the max C rating according to your criteria be lower if the packs were not being heated by the 2C charge rate just before they were discharged? If so, wouldn't that be a more realistic number?


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## guver

I've not seen any noticeable "warm-up" of a cell or pack at 2C charge rate. A couple of degrees maybe?

I routinely charge old worn out (1C labeled) high IR packs at 5-6C and newer (2-4C labeled packs) at 10C AND I allow these rates to continue PAST the cv stage until the pack is full. This indeed does warm them up to a nice useable temp.

Maybe I'm just not spending enough "time" to get the temp increase? That's a good thing.


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## Danny-SMC

The standard that I use is charging the cells at 2C with the ambient and cell temp at 22 degrees Celsius prior to the charge. Charging at 2C instead of 1C saves time and the change in IR is only 0.20mOhms on a low IR cell which equals a difference of 1C at most. In the end the goal is to use the same testing method on all cells that I test. So cell with lower IR will be able to have higher C rates. 


I personally feel heating packs at the races shouldn't be allowed as it's just one more thing that every one will do so if no one does it and they tech pack temps when they tech charge voltage this should keep things simpler.


----------



## Danny-SMC

*C rate labelling*

Recently I purchased two 3S/2200 flight packs from the same company. One is rated at 2200/25C and the other is rated at 2200/55C. Since I know that there is no way that 55C is possible I was curious to see what the 55C would be like compared to the 25C. 

To my surprise the difference in IR using the ESR meter is only 0.20mOhms per cell. This means that both packs are pretty much the same C rate. I will have C rate testing done on these packs tomorrow and I expect both of them to be 30C with no sag and possibly 35C but that needs to be determined. One thing for sure is the 55C pack will not be able to do much better than the 25C pack. 

This is a clever way for companies to sell more packs as they make a big batch of 30-35C cells and sell the ones with a bit higher IR as 25C for the customers who want to pay a bit less and then sell the lower IR cells as 55C and get more profit but in the end it's one batch of cells used for all packs. They also sell a 30C pack which I suspect uses the same cells as the 25C and 55C pack. 

The more I test cells/packs the more I see that the RC LiPo market is really messed up.

I just received some packs and cells today and it seems like they are all overrated by 5 to 10C using my standard and last week I got some packs that were rated at 20C by a factory and I'm getting 25C out of them. This really makes me wonder how much control these factories have on making the cells from batch to batch the same or how they test for C rate. 

All of this really makes me wonder about using IR as part of the rating of the future packs we want to release. Need to make sure the factory we deal with can get us cells within a respectable IR range.


----------



## guver

Danny-SMC said:


> Recently I purchased two 3S/2200 flight packs from the same company. One is rated at 2200/25C and the other is rated at 2200/55C. Since I know that there is no way that 55C is possible I was curious to see what the 55C would be like compared to the 25C.
> 
> To my surprise the difference in IR using the ESR meter is only 0.20mOhms per cell. This means that both packs are pretty much the same C rate. I will have C rate testing done on these packs tomorrow and I expect both of them to be 30C with no sag and possibly 35C but that needs to be determined. One thing for sure is the 55C pack will not be able to do much better than the 25C pack.
> 
> This is a clever way for companies to sell more packs as they make a big batch of 30-35C cells and sell the ones with a bit higher IR as 25C for the customers who want to pay a bit less and then sell the lower IR cells as 55C and get more profit but in the end it's one batch of cells used for all packs. They also sell a 30C pack which I suspect uses the same cells as the 25C and 55C pack.
> 
> The more I test cells/packs the more I see that the RC LiPo market is really messed up.
> 
> I just received some packs and cells today and it seems like they are all overrated by 5 to 10C using my standard and last week I got some packs that were rated at 20C by a factory and I'm getting 25C out of them. This really makes me wonder how much control these factories have on making the cells from batch to batch the same or how they test for C rate.
> 
> All of this really makes me wonder about using IR as part of the rating of the future packs we want to release. Need to make sure the factory we deal with can get us cells within a respectable IR range.


I have to say that I agree with you again. I have suspected that many differring "C" ratings within the same family were very similar actual "C" rates. The few I have tested show that the lower rated cells are far more accurately rated than the higher rated cells. 

 That's why I generally cheap out and buy the lower rated packs. 
Sometimes the Higher rated packs are heavier , but a dead giveaway would be identical weights.

Hey, keep it comin' . It's interesting. :thumbsup:


----------



## caalvord

*Battery temp*

Battery temp is monitored closely by BRL at all events they usually allow 10 degrees above room temp


----------



## Danny-SMC

That's why I want to use my own standard for C rate as it seems that the factories aren't really giving out the real info or maybe don't pay attention to the testing parameters. I know in China it can get fairly hot and I doubt that there using a controlled room temp as I have seen test results where the starting temp of the cells was 32 degrees Celsius and other tests it was at 23 degrees. In a recent test I did I went from 22 to 25 degrees and the IR dropped by 0.2mOhms. 

My biggest concern is that this will impact our sales if our C rates are lower than others. I wonder how many buy a 50 to 150C labelled pack just to show off and claim they bought the best pack. Maybe we need to offer different series. One with the actual C rate using my standard and the other series called BS series and just use inflated C rates. We've been selling low IR packs since we started selling Lipos so I know the performance of our packs are good so even if a customer wants to buy a higher C rate label the pack will still run good as good or better than other packs with high C rates on the labels.


----------



## guver

That would be a big concern for me if I was selling batts.

The word of mouth sales won't be a problem.
Those who watch the numbers will be a problem.
I would not like to see same packs labeled differently.
I just browsed your site and was surprised to see many 30-60C constant packs listed.
I think that an "actual" or "honest" rating would be nice along with a "previously rated as" or a "comparison rating" that consumer can quickly make a mental comparison to other vendors might be a possibility.

Two columns of "C" ratings for each series of packs? In the end most consumers do the quantity of research they are comfortable with and "trust" someone. Unless they are racing or pretty sharp they don't have a lot to compare to and have no idea if they got took or if they got a good deal. Most users do not have the capability to "test" 2 packs , let alone buy more than what they need.


----------



## Danny-SMC

Thanks for the your opinion on this as I know that some just want to buy the best label. This is why the ESR/IR meter is such a great device as it's pretty inexpensive and will give a very good idea of the performance of a pack.

Still not 100% sure how we will proceed from now on but all I know is the false claims need to stop. I got fooled into believing the factory as they showed me graphs at 60C but to my surprise when I finally was able to get my discharger done I figured out I was lied to. That being said I know for a fact that our 60C packs have very good IR and high average voltage so they are some of the best packs in the market. I just wonder what will happen if we release a new line up and these become 6000/30C instead of 60C if people will still want to buy them or will they prefer to buy 65C , 70C , 90C or 150C packs from our competitors. 

I just think this needs to stop and there needs to be a standard so factories and resellers stop with the marketing as it has gotten out of control and it doesn't seem to be slowing down as I keep seeing higher rated mAh packs with higher C rates coming out all the time.


----------



## Danny-SMC

*C rate tester*

Here are pictures of my C rate testing setup.

This setup allows me to discharge a cell up to 184amps. I use a precision current shunt and log the amps with the digital voltmeter to give me accurate mAh ratings as depending on the amp draw there is some drop.

The loads are CC-400 made by Camlight and are triggered when the GFX discharges the pack. I capture the real time data from the GFX then send the data into a CSV file which allows me to do graphs. The GFX voltage sensing leads are attached to the copper clamps using a true Kelvin connection so there is no voltage drop.

You can also see one of our cell and see how big the tabs are. Based on the info I got these are the widest tabs possible for the size cell we use. They are 15mm in width.


----------



## guver

Well that looks pretty good. The way you are doing graphs seems very well thought out. I especially like the plant life in the background.

I want 1 more cc-400 , but I need someone else to buy 2 more. Do you want 2 more? John gives a good price on 3 or more. I don't NEED another one , but would sure like one. It would allow me to do all the current I need for my packs.

I only ever saw wide tabs like those on some skinny 2.2 cells , but they came out at opposite ends of the cell. The cells weren't very good either. They are 15 mm wide too. 

You have a nice setup there. I've done a couple of 200 amp tests (on a pack with leads no less) , but I have to control the load manually when doing over 50 amps or so. 

I'm kinda on the fence about testing cells vs packs , they both have their place for sure. I also am on the fence about testing packs with the included leads and/or connectors. It just introduces such a variable into the mix.

It's not pretty , but it is fun.


----------



## Danny-SMC

I do everything in my living room while watching TV. 

The reason why I use the GFX as the discharger to control the loads is due to the GFX having voltage sensing leads which allows me to get a true Kelvin connection so there is no impact due to voltage drop because of how the cells or packs are hooked up.

Since the IR of the cells drops in half when putting them in parallel testing on cells means less Watts needed and the results will be the same as if you do tests on 2P setup. I believe results might be a bit better when testing a pack as there will be a bit more heat thus the IR should drop a bit more.

Our car packs have had these size tabs for a very long time.

I do have 3 brand new CC-400s in the box. I was innocent and believed in the C rates so I thought I may need to test at 360A on a 2S pack so I ordered enough CC-400s to be able to go that high. I will sell you if you want.


----------



## Danny-SMC

*ESR IR meter video*

I did a video showing the ESR IR meter in action.


----------



## CamLight

Danny,
Congratulations on getting the rig together and working so well! It's always great to see how the loads are being used. 
I'm really looking forward to seeing more test results!

John


----------



## Danny-SMC

I've updated post 6 which explains my C rate standard. I've added a new graph at 25C and a link to a youtube video showing the 25C test.

http://www.hobbytalk.com/bbs1/showpost.php?p=4114981&postcount=6


----------



## cneyedog

Danny, when do you expect to release a new cell in the future ? as in anything higher then 6000mah ? ....... just curious. When will you start using your new method of grading your packs. I would like to try one when you do ... :thumbsup:

Rich Boehmler


----------



## Danny-SMC

Will be releasing a new 2S pack with the new rating system early next month. It's going to be a 6500mAh. Will post info once it's ready.


----------



## cneyedog

Thanks Danny, looking forward to trying one.


----------



## rcgen

Are you testing 1cell as well?


----------



## Danny-SMC

I've tested some 1S packs but not sure if we will release any new 1S packs as that part of the market is not very big and if you don't offer the pack of the month then it becomes hard to sell them.


----------



## jdearhart

Danny, have you got an inline balancer for the GFX you'd recommend? I've been using the Great Planes wired up the way CE shows in their instructions but I've burned up two. A couple of my buddies have been through two also.


----------



## Danny-SMC

I'm not familiar with how CE recommends to hook up the balancer.

Where do you put the voltage sensing leads ? 

You may want to look into a Common Sense RC balancer. You just plug it into the balance connector of your pack. You would need to put the voltage sensing leads on the power connector.


----------



## jdearhart

Danny-SMC said:


> I'm not familiar with how CE recommends to hook up the balancer.
> 
> Where do you put the voltage sensing leads ?
> 
> You may want to look into a Common Sense RC balancer. You just plug it into the balance connector of your pack. You would need to put the voltage sensing leads on the power connector.


I've got it wired the way it is shown on the lipo users manual addendum. The way it is shown in the second picture here:

https://www.competitionelectronics.com/media/pdf/LiPoGFX_Addendum12_08.pdf


----------



## Danny-SMC

There is 2 things you can do. One is to buy a Common Sense balancer and charge your pack without the balancer and at the end of the charge you put the balancer on the pack and balance it out. Once it's balanced it will stay balanced for many cycles. Just repeat this step once in awhile to keep in balance. This will require that your voltage sensing lead be attached to the balance connector to get the proper voltage sensing.

The other way is to attach the Common Sense balancer to the pack while it's charging through the balance connector. This method will require you put your voltage sensing leads on the power connector. You can put them on the side of the male Deans connector. Due to this you may want to pick the first solution as this will be the easiest way.


----------



## TeamGoodwrench

jdearhart said:


> I've got it wired the way it is shown on the lipo users manual addendum. The way it is shown in the second picture here:
> 
> https://www.competitionelectronics.com/media/pdf/LiPoGFX_Addendum12_08.pdf



In that second picture, it looks like you are taking the 12 ga. power wires and running them into the balancer, and then the balancer output is connected to the pack power leads with those little like 20 ga. ? wires ??? 

I'm not sure I'd want to put 10 amps through those ??


----------



## TeamGoodwrench

Danny-SMC said:


> I'm not familiar with how CE recommends to hook up the balancer.
> 
> Where do you put the voltage sensing leads ?
> 
> You may want to look into a Common Sense RC balancer. You just plug it into the balance connector of your pack. You would need to put the voltage sensing leads on the power connector.


Could you post a picture of the wiring if using a Common Sense balancer in-line with a GFX ?

Thx


----------



## Danny-SMC

I don't have pictures as I don't use this balancer but I have seen guys who use it.

You don't plug it in-line with the GFX. Just plug it into the balance connector of the pack and plug the GFX like there was no balancer. You will need to have the GFX sense leads attached to the power wires or build some sort of adapter to tap into the balance connector once the pack is plugged into the balancer.

I think just using the balancer at the end of a charge once in awhile will keep the pack in balance as packs will not get out of balance that easily.


----------



## jdearhart

TeamGoodwrench said:


> In that second picture, it looks like you are taking the 12 ga. power wires and running them into the balancer, and then the balancer output is connected to the pack power leads with those little like 20 ga. ? wires ???
> 
> I'm not sure I'd want to put 10 amps through those ??


LOL! No, the balancer will only handle 7.5 amps. We charge them at 6 amps.


----------



## jdearhart

Danny-SMC said:


> There is 2 things you can do. One is to buy a Common Sense balancer and charge your pack without the balancer and at the end of the charge you put the balancer on the pack and balance it out. Once it's balanced it will stay balanced for many cycles. Just repeat this step once in awhile to keep in balance. This will require that your voltage sensing lead be attached to the balance connector to get the proper voltage sensing.
> 
> The other way is to attach the Common Sense balancer to the pack while it's charging through the balance connector. This method will require you put your voltage sensing leads on the power connector. You can put them on the side of the male Deans connector. Due to this you may want to pick the first solution as this will be the easiest way.


Thanks for the help!


----------



## Danny-SMC

1S-6S ESR meters back in stock.


----------



## Danny-SMC

I finally released info on our new line of packs using our own C rate standard.

http://www.hobbytalk.com/bbs1/showthread.php?p=4146193#post4146193

I really hope this new line of packs will help show how C rates are just used for marketing. I have a 65C and 90C pack coming in tomorrow from our competitors and I will compare them to our new Premium Certified 25C pack.


----------



## Danny-SMC

*4mm connector test*

I was finally able to test our low resistance 4mm connectors versus the typical split/swivel type connector that comes with most cheap inboard style packs. I knew the split/swivel type had more resistance as I had done a test in the past but using the ESR meter I can easily show the difference in resistance.

I took a 5400 pack with storage charge and used the good 4mm connectors we sell and tested the first cell. I took the same pack using the high resistance split/swivel type and tested the first cell.

SMC connector: 2.80mOhms

Split/Swivel connector: 3.80mOhms.


A 1.0mOhm difference is a significant difference as this means the voltage will drop 0.05 volts under a 35 amp discharge. The higher the amp rate the more drop there will be. On a 5400 pack 1mOhm is equal to 4C so basically a 24C pack using higher resistance connectors will run like a 20C using good connectors.


----------



## Goodwrench29

Danny..pm


----------



## sportpak

Danny-SMC said:


> I finally released info on our new line of packs using our own C rate standard.
> 
> http://www.hobbytalk.com/bbs1/showthread.php?p=4146193#post4146193
> 
> I really hope this new line of packs will help show how C rates are just used for marketing. I have a 65C and 90C pack coming in tomorrow from our competitors and I will compare them to our new Premium Certified 25C pack.


Any details on the battery run off?


----------



## Danny-SMC

I will have some cycle life data on some of our competitors 90C and 65C pack by the middle of this week. Cycle life testing takes a long time as I put 50 cycles the pack. I'm also testing cells/packs from other factories so my equipment is pretty much being used all day long. 

I think the results I will show will be very interesting and prove once and for all that not all Lipos are the same.


----------



## Danny-SMC

Here is a Poll I setup and would like to have input from as many as possible.

http://www.hobbytalk.com/bbs1/showthread.php?t=362321

Thanks.


----------



## Danny-SMC

I just posted some results on 2 different packs I just finished testing. I will post more results as they become in available.

http://www.hobbytalk.com/bbs1/showthread.php?p=4166540#post4166540


----------



## Danny-SMC

*SMC Hardcase Race Pack Comparison*

When talking with some customers/racers I realized that many don't understand that a higher mAh pack will have a better voltage curve due to the extended mAh. This will only be true if the cells are made to have the lowest possible IR. If the pack is made with lower C rate/higher IR cells then it will not have a better curve than a lower mAh pack with lower IR.

You can look at the graph and see how mAh impacts the voltage curve. All packs are tested on the same GFX at 35 amp discharge.

Hope this helps everyone better understand the difference between the different SMC models.


----------



## Blash

Danny-SMC, I want to take a moment and thank you for all of the battery information you have put forth, you do a great job explaining C-ratings and such so as a person with "0" knowledge of LIPO batteries can make an informed decision, i have purchased numerous 2 and 1 cell LIPO's over the past 2 years from several different companies (including yours) and have found that some of the most expensive purchases have been the most disappointing. I treat every battery exactly the same as far as charging/discharging and storage methods and yet my most expensive 2 cell packs (4 each) have puffed to the point that I must dispose of them, prior to the puffing I could see that they were degrading much faster than the lower priced units, very disappointing because they cost me 120 dollars a piece, yet several of the midpriced and low end 2 cell LIPO's continue to perform flawlessly with no signs of degrading. You have opened my eyes and I look forward to dealing with SMC for my future battery needs. Rich


----------



## Danny-SMC

Glad that you like the info I'm providing as I really want to help everyone better understand Lipos. The way I see it there is three important factors when trying to rate or chose a LiPo. One is performance. If you race or want your RC ride to go as fast as possible you want to buy a pack that has low IR so you will get more speed out of the pack. The second is cycle life. You want a pack that will not lose it's capacity or increase it's IR to fast. The third is pricing. Buy packs that have the best price with good performance and good cycle life.

One thing everyone should understand is high performance can come at the expense of cycle life. As with anything that pushes the limits to extract the most out of it this can create potential issues. A few factories are using a certain material that lowers the IR and costs less so there cells have an increase in performance but that increase comes at the expense of the mAh dropping off very fast.  You can see the 6500/90C pack I tested as it uses this material. There is a fine line between performance and reliability.


----------



## Danny-SMC

*Interesting C rate info.*

As most of you know I've been doing allot of tests on various Lipo packs and I recently got an email from a Lipo factory that I thought was very interesting in regards to C rate and the various claims.

Here is a copy of the email. 

Hello Danny,

In the Lipo battery industry, there's no real 70C~90C .... you know well that those are marketing stuff.
The fact is that, the positive/negative tags of Lipo cell would be burnt off at high current.
The chemistry & cell packaging materials only support a real 40C~45C indeed.

With the above background, please find our internal guidelines on C-rating as follow :
1) for 30C or below, the cell models would be subject to continuous discharge at specified C-rate, where we expect MPV 3.40~3.45V.
2) for 40C and above, you know well that the cells would have gas formation upon 100~120Amp continuous discharge.
3) those Hi-Power cells would be tested for Pulse-discharge at specified C-rate -
40C models Pulse 40C x 30sec
50C models Pulse 50C x 10~15 sec
4) along with that, the Hi-Power cells would go for 20C/30C continuous-discharge, and compare their MPV.



 
This is some very interesting info. Not sure I agree on the method they use to claim 40C or 50C but the fact they tell me the truth about C rates and testing is very good. I truly believe that the best method to rate a Lipo would be to use IR but then again that can easily be manipulated and the factories and resellers would quickly start claiming lower IR. That being said it could easily be tested with the ESR meter unlike C rate which is very hard to test.


----------



## WNRacing

So Danny, they are admitting that their C-rating claims are false and that it is in-fact not a constant C-rate (as most advertise), but a "burst" rating being shown on their packs? 

I wonder if they'd be so willing to give this information to their consumers?


----------



## Danny-SMC

Actually they did give this info to me as they know I do my own testing and can figure out the C rate of any cell. Not sure they will inform others. 

4 years ago C rates were basically used properly and with honesty but in the past 4 years claims have gotten out of control and used as marketing. 

I was just informed a few weeks ago that one of the customers who buy from the same factory we buy from has ordered packs with new labels rated at 100C this is the same pack we claim is 25C based on my testing method. 

I've posted allot of good info on this site and I hope this can help everyone better understand what is going on in this market. 

Bottom line most 2S Hardcase style packs are 15 to 30C using my method of C rate testing listed in the first few posts on this thread.


----------



## guver

I think those 100C labels are more expensive. They must be.


----------



## Danny-SMC

I'm pretty sure the packs will be more expensive than our truly rated 25C packs but I'm sure some will want to try them as they have 100C labels and this reseller has been selling the same pack as 65C. Just do a new label and sell the same pack. Pretty good marketing.

This is why using the ESR meter to get IR values is very important in my opinion. The only way for the C rate to increase is for the IR to decrease. If true 50C , 70C , 90C , 150C packs would be possible the IR would have to be lower than our 25C packs and I know our 25C packs have very low IR and most likely as good or better than any other pack in the market at this time.


----------



## Danny-SMC

*Factory Spec Series*

*SMC Factory Spec *

"Factory Spec" is a new line of high performance packs that use the factory specified values for C rate and capacity.

As with all SMC batteries, these packs are manufactured by factories which are known for supplying high performance, reliability, and quality.

6570-2S2P In stock now only 59.95 on special.

6570-2S2PT Due in on 09-21-12 only 59.95 on special.

6570-4S2P Due in on 09-21-12 only 114.95 on special.


----------



## Roadsplat

Any new 1S packs coming with the new rating system?


----------



## Danny-SMC

Actually we just released a new Series called Factory Spec. All new packs will be under this series and yes we will release a new 1S pack. The launch is delayed as the first batch had some issues with mAh dropping off to fast.


----------



## johnqpublic

So have you abandoned your true C rating? What is the true C rating of the Factory Spec packs?


----------



## Danny-SMC

Yes as only the serious customers who take time to read and understand bought packs with our C rate testing standard. Unfortunately the majority of racers and customers want to believe in hype and marketing so I guess we have to comply or accept selling less packs.

I'm not testing the Factory Spec packs for C rate just labelling them based on the specs provided by the factory. I do test for cycle life and performance to make sure these packs are high performance and have high cycle life. With our competitors claiming 90C , 100C and 150C I guess were still behind but I don't feel it'a appropriate to inflate the labels over what the factory claims for specs.


----------



## johnqpublic

Thanks for the fast reply. Will these be available w/ the deans plug?


----------



## Danny-SMC

Traxxas but we can always switch it out for Deans. Just add that you want a deans in the comment section when checking out.


----------



## horsedog

Why do identical batteries weigh up to 10 grams more. Red spec pack. One is 112 another is 122?


----------



## Danny-SMC

Difference in batches can result in different weights plus packs within a batch can also fluctuate.


----------



## Danny-SMC

All 3 models of our new Factory Spec 6500-70C are now in stock.

Were so confident that these packs are as good if not better than any 6500-7000 pack that were offering a Satisfaction Guarantee. So stop paying to much for 90C , 100C or 150C labels.

Here are the details of our guarantee.

*On select packs we offer a satisfaction warranty. If your not satisfied with the performance of these select packs you can return them to us in the first 2 weeks from date of purchase. The price of the pack will be refunded. The customer will be resposnible for the shipping charges and return shipping. If you have any questions regarding this guarantee please contact us.*

We have a pole up on the SMC Facebook page if you guys won't to drop buy and vote to give us your opinion that would be great. 

http://www.facebook.com/smcracing


----------



## Danny-SMC

http://www.hobbytalk.com/bbs1/showpost.php?p=4304615&postcount=10


----------



## Roadsplat

Looks great Danny. How long before the 1s will be available?


----------



## Danny-SMC

Will be listing some 1S info soon. Waiting on cycle numbers.


----------



## Danny-SMC

New 1S info posted on at the link below.


http://www.hobbytalk.com/bbs1/showpost.php?p=4304682&postcount=11


----------



## Danny-SMC

*Battery Dyno*

I just built a battery dyno which is basically the McPappy Chassis Dyno without the pod and using motor to motor for the load. I hope this will allow me to give a RPM rating for the different packs we offer. This should help the regular customer who isn't familiar with GFX data or IR and voltage curves to better understand how one pack is different than an other.

Special thanks to Jame Van Horn of McPappy Racing for the help.


----------



## shadowwalker

Danny-SMC said:


> All 3 models of our new Factory Spec 6500-70C are now in stock.
> 
> Were so confident that these packs are as good if not better than any 6500-7000 pack that were offering a Satisfaction Guarantee. So stop paying to much for 90C , 100C or 150C labels.
> 
> Here are the details of our guarantee.
> 
> *On select packs we offer a satisfaction warranty. If your not satisfied with the performance of these select packs you can return them to us in the first 2 weeks from date of purchase. The price of the pack will be refunded. The customer will be resposnible for the shipping charges and return shipping. If you have any questions regarding this guarantee please contact us.*
> 
> We have a pole up on the SMC Facebook page if you guys won't to drop buy and vote to give us your opinion that would be great.
> 
> http://www.facebook.com/smcracing


holly crap this company really dont put the screws to no one


----------



## riley3393

Thats just good service by one of the best in the business. Its what all companys should strive for.:thumbsup:


----------



## Danny-SMC

Thanks for the kind words. When the first Turbomatcher came out many years ago I started matching cells for me and my friends so we could have good packs and I could sell good packs. 20+ years later I still try and sell the best possible packs and do detailed testing to make sure of this. Problem is that I have never been one to come out with gimmicks or stupid marketing so in this new market it has hurt me allot. Hope with social media we can get the word out that were the real deal as our pricing is lower than others for the high end packs and were working on releasing budget friendly packs.

Thanks to everyone who has supported me over the years.


----------



## Danny-SMC

As most of you know by now I do allot of detailed testing on packs. Recently a reseller/factory approached me and sent me a price list. Based on the specs they had I noticed the packs were on the heavy side so I decided to order samples from them to see how they compared to other packs I tested. The samples came in and here are the results on 2 of the packs. 

*6000-30C-2S Inboard:* 

Weight: 314gr Weight on Spec sheet: 312gr

IR at end of 12 amp charge: 3.20-2.92 GFX data: 6319mAh - 7.42 - 5.4IR

*6000-60C-2S inboard:*

Weight: 314gr Weight on spec sheet: 338

IR at end of 12 amp charge: 3.08-3.28 GFX data: 6270mAh - 7.41 - 5.5IR

This is a perfect example that shows how messed up the Lipo market truly is. They use 1 type cell and label it at 30C , 40C , 50C and 60C. Then some companies who buy from these reseller/factpories add to these specs to have even better looking specs.

This isn't the first time I see this. Also explains why some of the popular online discount Lipo sellers have so many different models.


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## Danny-SMC

Here is an interesting post I just did in the Oval section.

http://www.hobbytalk.com/bbs1/showpost.php?p=4313378&postcount=21


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## Danny-SMC

*5000-30C Budget pack*

We just released our first budget oriented pack. This pack is a 5000mAh 30C Hard Case pack with real Traxxas or real Deans connector. Power wires are 10AWG and the balance tap is the JST-XH.

In my cycle life testing this lower priced pack dropped 2% over 50 cycles which is very good especially for the price. 

Were doing a special launch price on these for 24.95

http://www.smc-racing.net/index.php?route=product/product&path=67_78&product_id=117


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## WIGMAN

Hey Danny, love this thread.....just wondering if you are going to have any 2s shorty packs for sale any time soon.
Thanks for all you have done on here. Priceless info.


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## Danny-SMC

Yes we have a new 4300-50C that will sell for 34.95 and a full blown race pack that is 4600-70C for 54.95. I personally think that the 4300 should be fine for mod guys and the 4600 for stock as the voltage curve will be higher due to lower IR and higher mAh.

Also have a regular size 6500-60C we plan to release at 39.95 this will be a great budget race pack or play pack for those who want extended play time and performance over the entry 5000 packs.

These 3 packs should be available in early November.

Spent the last year studying and testing packs and finally have made a decision to sell SMC direct off our website at best possible prices for the models we offer. Hope the word gets out there as I truly believe we have some great packs to offer at great prices.


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## Danny-SMC

500 Facebook Like Contest

Were offering a 2S pack of your choice to the winner of our 500 like contest. We will pick one random person as soon as we hit 500 likes on the SMC Facebook page.


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## bertottius

Great thread going here. I am a long time racer who is just getting back into the game after a 10+ year layoff. I used your Nickel batteries back in the day and I loved them.


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## Danny-SMC

Hard for me to comment as I have never tested one. I'm sure someone has and can maybe share some info. I personally have my doubts that you can change a Lipo but I could be wrong.


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## Nozzle216

I just wanted to say thank you for being here and involved as you are. As a guy that used to be into racing years ago, before any of this brushless / lipo stuff, it is all overwhelming. SMC is a great company and I almost EXCLUSIVELY ran your NiMH's (matched of course) when I was into electric touring and 1/12 scale around 10 years ago. 

Reading about all the new technologies and trying to learn (re-learn) everything is daunting. I now know where I will turn for my battery needs. SO HAPPY that I found this thread and to find you are still in the game and giving us the TRUTH! I just crossed off one unknown from my list of what to buys. 

Thanks again!

Cory Wilson


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## Danny-SMC

Thanks for your support. I believe in being able to earn a living and still be honest and helpful. That has become allot harder in the Lipo market with all the stupid C rate claims and relabelling of the same packs but I try do things a bit differently but had to adapt on some aspects. 

You may find this thread interesting if you haven't seen it already. Shows how C rates mean nothing.

http://www.hobbytalk.com/bbs1/showthread.php?t=362697

If you have any questions feel free to ask on this board , PM or via email. The new technology is actually much better and easier in my opinion.


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## OLDY GUY

*Were to buy 4025S 1 cell 4000*

I went to your web site and cant find them.


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## Danny-SMC

Out of stock pretty much everywhere until the end of this month. This pack is up 100% in sales this year which is good but hard to forecast for such a huge increase in sales. The problem will be resolved as we have many packs on order for MSA who supplies all the shops and race tracks.


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## STLNLST

The shorty packs have been a real hit out here in Northern California in the 17.5 class. The racers I have let run them are decent club level racers so the feed back has been great. I just gave all the info to Big Mo this morning. My car was never down on power from statr to finish. At the street price you mentioned racers will flock to these. Keep up the good work.


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## Danny-SMC

Thanks for the feedback and glad to hear the packs are doing well. You tested the 4300-50C which will be in by the middle of November.

We have the 4600-70C coming this week but the mAh is 400 or so lower so we will sell this first batch at 34.95 instead of the 49.95 normal price.

I believe the 70C pack should be better suited for stock racing and the 50C is for mod or low traction tracks. The 4300-50C will be at 34.95.


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## STLNLST

There was also the 4100 pack. Both were good packs. Can't wait to try out full production packs as I felt these may have been 2/10ths a lap slower due to not having a SMC label on them.....LOL 
We have a 2day race coming up next month in Chico, Ca.....I may have to steal them back from Mo:hat:


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## JOHNNYTANLINE

Danny, you mentioned a "small" difference in one (batch) of batteries, to
another.

Do todays lipos have any sort of "code" on their lable, like ni-cads & nimhs
used to???

You know, like Budweisers "born-on-date"


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## Danny-SMC

No there is no code on the outside but the cells might have a date stamp on the,. The differences we're talking about are not big and as far as SMC goes if we see there is an issue with a batch we sell it at a lower price and let everyone know why. Just sold 50 packs of short case 4600-70C that are off by 400mAh but sold them 15 dollars less.


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## Danny-SMC

New packs added to our website and on special.

Race Formula packs have lower IR.

http://www.smc-racing.net/index.php?route=product/category&path=67_78_84

Regular Factory Spec. Great price on some good packs.

http://www.smc-racing.net/index.php?route=product/category&path=67_78_85


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## linakeen

great i like it


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## Jsnow51

Can I get DODC batterys from you because no one has them instock??? Need asap or do you have them in stock??????


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## Danny-SMC

We don't have stock on this model at this time. You should try contacting Custom Works as they should know who has these packs in stock.


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## jdearhart

Jsnow51 said:


> Can I get DODC batterys from you because no one has them instock??? Need asap or do you have them in stock??????


Have you tried Bumps and Jumps?


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## bertottius

*LiFe*

I just bought one of the 220 mah receiver packs from someone and I was wondering how many amps to charge it at. I have a TP 820 charger that is LiFe capable. Any help would be appreciated.


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## Danny-SMC

You can charge it at 1 amp.


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## bertottius

Thanks! :thumbsup:

Any other care instructions I should know about?


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## Danny-SMC

Make sure to charge it in LiFe mode and your good to go.


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## bertottius

Very cool. Thanks!


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## NV529

what is the difference between the Race formula and factory spec? (besides C rating)


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## Danny-SMC

Race Formula come from one factory and the other packs come from another factory which makes cheaper packs.


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## phea

Was wondering when the 2s Race Formula packs are going to be back in stock. Is there a email newsletter or auto notification area to sign up for that?


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## flag172

as any one heard or seen Danny Sullivan.Ive sent him a few P.M. but no answer and he as not been here since February 21th
Danny Flag/72


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## race71

He posted on his SMC Facebook page the other week try that maybe


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## flag172

race71 said:


> He posted on his SMC Facebook page the other week try that maybe


whats the face book adresse. I tried SMC and didn't find anything


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## wait a minute

:wave:try google first danny. it helps. :thumbsup:

http://www.smc-racing.net/


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## swtour

FB https://www.facebook.com/smcracing


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## gt2t4

......


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## flag172

thanks guy's got hold of him:thumbsup:


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## gordie b

When is the web site gonna have batteries back in stock? Need some for summer dirt oval starting soon.


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## gordie b

Never mind


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## NCFRC

Quote from facebook ,,,,

I know some of you are disappointed that our latest shipment sold out pretty much instantly. This shipment was ordered on January 28th while we were expecting another shipment in early February. Hard for us to forecast ahead of time so this was just a small shipment. The Chinese New Year vacation really makes it tough to get orders in February and March. We have another shipment that will ship out in 2 weeks. We also have a good shipment of 70C packs we hope will arrive next week.

Seems like SMC packs are becoming very popular due to the performance versus price of the packs. This was our goal to offer the best possible packs at the best price. Now we need to adapt to the demand but I would like to explain why we do run out of packs.

1) We're committed to supplying fresh packs. This means we don't want to order a model and have it sit for to long.

2) We check each pack to make sure it's in the spec range we expect. If we order to many of a model and the specs are out of that range we need to sell these as out of spec at an extra discount. This is another reason why we must be careful with what we bring in.

3) We supply packs with real Deans , Traxxas and 4mm inboard. We could do like some of our competitors and just offer packs with a crappy tube style connector but we want to offer a pack that is ready to use with the best connector possible. If we could order only one style connector for each model this would help us better keep up with supply but that isn't the case.

We don't want to increase the price or stop checking the packs to make sure they are at the proper specs. We hope everyone can understand that we're doing our best and we will eventually adapt to the high demand.

Thanks,
Danny Sullivan


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## KRITER

*Reciever Pack*

Danny, I am looking for the hard case Lipo reciever pack are they still made? Can't seem to find one on your site. Thanks, Steve "KRITER" Kritikakos. :wave:


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## teamatlas

any word on the next batch yet ?


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