# Li-Poly Rumors



## Trixter (Oct 8, 1998)

I talked with a friend of mine that said some of the Brushless guys are runnung with the gas guys in 30 minute mains (without battery changes) and are keeping up and some times winning these races. What's with that????


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## RCRacer45s (Oct 22, 2002)

wow...very impressive :thumbsup:


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## The Jet (Sep 25, 2001)

Hmmm, rumors will be rumors. To my knowlage LiPo batteries can't handle high discharge rates just yet, and to keep up with a reasonably fast nitro car, you would HAVE to draw some considerable amps, which I don't think the LiPo batteries can do. Not positive, but pretty sure :thumbsup: .

Later, Bret


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## XXX-SCapece (Apr 28, 2004)

The rumors true. I've personnally seen a LiPo brushless T4 run w/ and finish the A-mains in gas trucks.


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## tommckay (Sep 26, 2001)

It would all depend on the size of the track in my opinion. If it's fairly tight & technical the electric has an advantage. Li-Po cells are developing rapidly, I ran some in my Mini-T and was easily able to get 13min or so & they were low Mah cells. Now they have 7.4v Li-Po cells that rate 8000Mah.

Met a guy that had 2 of them in an E-maxx and was getting 25 minutes plus in run time, he talked to some people and was told when he switched to Brushless his runtime would increase to 40 minutes. Drawback is, you can't "quick charge" them as fast as NiCd & NiMh's, you must be careful how far you discharge them, they are finicky as to charging, you need to be careful in handling them because they are volitile, and the 7.4v 8000Mah packs are running $150 each!


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## tommckay (Sep 26, 2001)

Well, maybe $150 ain't all that bad.... 1 Li-Po like that could replace 4 regular race packs easily. If they give 30 min run time (conservative estimate) you could run three 5 minute qualifiers and a 5 minute main on 1 pack without recharging and still have 10 min run time left. And with 2 packs you could practice your butt off and really tick the guy off that's waiting for your frenquency! 

The hobby is evolving..... Think of it, invest some $$, you could buy a Brushless system, a couple 8000Mah Li-Po packs with Li-Po specific charger, the new 2.4Ghz transmitter module & tranciever, go to the track and practice for 30+ minutes straight without stopping & no one to complain that you're hogging their frenquency. Then run 3 Q's & a Main without recharging anything. That would be cool (and actually possible now).


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## ChrisHarris (Feb 26, 2002)

I like the idea of doing a gas truck main and just zipping by while they pit to refuel! Don't know how much time you would make up over 30 minutes but it would count for something!


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## XXX-SCapece (Apr 28, 2004)

Think about this:

the average racer has around 5 matched packs- $300
the average racers has around 5 motors - $200

So for 500 dollars you can drive your car for 40 minutes. Assuming that you replace your motor and battery every 8 min. A lipo powered brushless can go about 45 min. w/ modified power.

Lipo battery: $150
Brushless motor and esc: $250

So the total is 400 for brushless and 650(including lathe) for brushed power. 

I think we are seeing the future of our hobby.


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## Trixter (Oct 8, 1998)

Jet: Come on in the water is fine. Make the break to Brushless.


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## FASTALJR (Sep 27, 2001)

Lipo`s can handle some quite a bit. especially when u start stacking them I know my himaxx brushless draws some serious amps at full power. and I`m using a 3 cell 2100mh pack, and I am getting at least 10 minute flights. Airplane guys are using them readily. As I end I quote from a Powerman 5000 Lyric

"The Future has arrived...Are you ready to go????"


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## The Jet (Sep 25, 2001)

FASTALJR said:


> and I`m using a 3 cell 2100mh pack, and I am getting at least 10 minute flights.


I assume you meant 2100Mah. If so, 10 minutes with 2100mah batteries, no matter the voltage would be somewhere in the 10 amp draw range  .


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## HOOPD1 (Sep 25, 2001)

Im with the Jet on this one,as soon as they make a LiPoly that will take a 50amp+ draw without blowing a hole in my body Ill be the first in line for them.


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## Trixter (Oct 8, 1998)

A little research tells me that we are not too far off.


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## Trixter (Oct 8, 1998)

HOOPD1 said:



> Im with the Jet on this one,as soon as they make a LiPoly that will take a 50amp+ draw without blowing a hole in my body Ill be the first in line for them.


I think they already do.


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## hankster (Jan 1, 1998)

How about 58 Amp max, 44 amp continuous at 4200mAh? Weight 6.8 oz and 7.4 volt


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## PITBULL (Sep 25, 2001)

Jason Shulman just won in the aerobatics class at the 2004 nationals in Muncie Indiana .He had the only elec. powered airplane in the entire field from intermidiate to the pro's.
His airplane had a 22 inch prop with a Hacker C50-14xl 6.7:1 motor in it. I have seen him fly it. It is just as powerfull if not more powerfull than the nitro and gas burners.I attended the 2004 nationals in Muncie this year and competed in the funfly event. Got 1st in my class.Dont worry I also race r/c cars lol.If you ever get a chance to take a break from racin go to one of the big rc plane events.Prolly the biggest in the world is held in Woodruff S.C., its near Greenville.The technology is mindbogling. I think you will be amazed at what you will see..They have a huge vender area.There was even one vender that had some rc car stuff for sale.


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## The Jet (Sep 25, 2001)

hankster said:


> How about 58 Amp max, 44 amp continuous at 4200mAh? Weight 6.8 oz and 7.4 volt


Hank, the amp draw sounds about right for 19 turn racing, but do they make a 4 cell equivalent, and what's the size???

Later, Bret


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## FASTALJR (Sep 27, 2001)

Brett there is not a set size, the cells are all different sizes. A 3s1p 2100 mah(3 cells 1 pack) is about 3 inches long, and about an inch wide, and about 3/4 inch thick. I lost the motocalc results I had for my himaxx brushless with my 3 cell 2100, but it was in the high 30`s for amp draw at full power, I`m almost pushing the speedo limit with the setup. But I do live up to my screen name in some form of R/C:thumbsup:.


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## PITBULL (Sep 25, 2001)

The Jet said:


> Hank, the amp draw sounds about right for 19 turn racing, but do they make a 4 cell equivalent, and what's the size???
> 
> Later, Bret


 www.fmadirect.com
the above website has just about all the info you wiill need concerning lipo's
and the accessories used with them,,


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## hankster (Jan 1, 1998)

LiPo cells are 3.7 volts per cell, so you have 3.7 volts, 7.4 volts or 11.1 for a 3 cell pack. The size for a 2 cell pack is .34" x 2.1" x 6.9"

Some info and cool stuff can be found at http://www.robotmarketplace.com


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## irvan36mm (Oct 2, 2001)

Hank or Pitbull- Are these LiPo batteries compatible with our car speedos like Novak,Keyence,LRP,etc. Or would we have to use a LiPo-specific speedo,as found in R/C planes? I know some of the brushless guys in the first post were using these batts in their cars,but did they have to do any additions or mods to their electronics setup (besides the brushless speedo)?
-George


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## hankster (Jan 1, 1998)

No modifications should be required as most car ESCs can handle 7 cells. 6-cell NiCad = 7.2v 7-cell NiCad = 8.4v. 2-cell LiPo = 7.4v


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## PITBULL (Sep 25, 2001)

here are some transmitter batts. for M8s and JR 
www.htbatteries.com:thumbsup:


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## PITBULL (Sep 25, 2001)

irvan36mm said:


> Hank or Pitbull- Are these LiPo batteries compatible with our car speedos like Novak,Keyence,LRP,etc. Or would we have to use a LiPo-specific speedo,as found in R/C planes? I know some of the brushless guys in the first post were using these batts in their cars,but did they have to do any additions or mods to their electronics setup (besides the brushless speedo)?
> -George[/QUO
> 
> Irvin this is another web addy for some good stuff about lipo's
> ...


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## Mac The Knife (Jul 23, 2002)

The only difference between a conventional Esc, and one with a Li-Po option, is that the LiPo escs have a voltage cutoff that you program for the number of cells that you run. If you discharge a LiPo cell below 3 volts per cell, it ruins them.


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## jajnmj (Apr 1, 2004)

*lipo*

They say that it ruins them below 3 volts, but i have ran them till they dump in my mini t and has had no ill effects on power or runtime i think the reason they say that is for liability reasons with the fire hazzards of lipoly's. I also charge mine with a converted cell phone charger made for lithium ion batteries. They take around 3 hours to charge like this but who cares when i race them i charge before i go to the track run 3 3 minute qualifiers and a three minute main and still can drive for more than 30 minutes after that!!!!.
This is with a 2 cell 7.2v thunder power pack. for mini's i can't say enough good about them!!!!! just my 2 cents though.............. :thumbsup: 






Mac The Knife said:


> The only difference between a conventional Esc, and one with a Li-Po option, is that the LiPo escs have a voltage cutoff that you program for the number of cells that you run. If you discharge a LiPo cell below 3 volts per cell, it ruins them.


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## glassdoctor (Apr 11, 2002)

I have some Lipo cells on order, and I am planning to get some more. I will try them in several different cars... 1/10 buggy, 1/8 buggy and emaxx.

Lipos do have the power needed for cars, you just have to find the right ones. They are up to 6000mah single cells now, with 10C discharge or better. Do the math... that's 60A current draw. Or you can parallel like 2 4400 cells and get 80-100 amps...

Even our GP3300s can't handle 100A without bad voltage drop, and excessive heat. 

"super" lipos are beginning to appear NOW.


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## Trixter (Oct 8, 1998)

What are you going to charge them with?


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## irvan36mm (Oct 2, 2001)

PITBULL said:


> irvan36mm said:
> 
> 
> > Hank or Pitbull- Are these LiPo batteries compatible with our car speedos like Novak,Keyence,LRP,etc. Or would we have to use a LiPo-specific speedo,as found in R/C planes? I know some of the brushless guys in the first post were using these batts in their cars,but did they have to do any additions or mods to their electronics setup (besides the brushless speedo)?
> ...


Hank & Pitbull- Thanks for the info,guys! I'll check the hobby-lobby site out!
-George


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## purehobby (Feb 4, 2005)

Lithium Polymer is now capable of the discharge rates needed if you take for example the PQ2-S4400N's I carry they are a 12c (52amps)continuous although i would never recommend maxxing it out it will deliver 85% capacity at this rate. if you have any questions feel free to take a look at our website www.purehobby.com or email us at [email protected] 
Robert


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## racerrandy (Nov 23, 2002)

http://biz.yahoo.com/iw/050210/080729.html

Check out this link, its very interesting. Sounds like things are really going to get better!

Later,Randy


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## tommckay (Sep 26, 2001)

Very cool - 
"A key requirement to the above applications is the ability to recharge the battery very quickly, for example in a few minutes. Current Li Ion batteries are incapable of such quick charge times because of the chemistry of the anode materials. Altair has found a solution to this with their nano-sized lithium titanium oxide."
"Altair's nanomaterials, which have a virtually zero strain crystal lattice, eliminate the main cause for battery electrode material fatigue, which limits rechargeable battery life, increasing the number of recharge and discharge cycles from a few hundred to many thousand cycles"

A long run times out of a quick charging battery that will last thousands of cycles. Sounds good, but the article didn't mention a high discharge rate. I imagine there would be if it can be charged quickly it should discharge quickly as well.


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## hankster (Jan 1, 1998)

There is an article in RC Driver this month about a new Li-Poly battery/charger system available. The 3200mAh pack can discharge at 64 amp continous and can be charged to 90% of capacity in 20 minutes. It's pretty cool because it actually charges each cell seperately so each cell never overcharges and each cell gets the maximum charge it can hold.

Looks like Li-Poly will make a big change in RC in a couple years just as '05 will be the year that brushless really becomes popular.

The charging system (charge each cell seperately) is something that RC chargers should have done long ago. I've talked to a few charger manufacturers about it and they said it is not something that racers want.... I bet these new cells & charging systems will force a manufacturer to make one.


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## purehobby (Feb 4, 2005)

It will be very interesting to see what the future brings for Li-polys. I know manufactures are constantly looking at the developement of a new polymer battery. 
20 minute charge time would be great!!! If the batteries are also capable of a 10-15c discharge.
As for the individual charging socket the Poly-Quest batteries do have a seperate Tap coming out so you can charge/balance individual cells. Also offers a Protection circuit module that can connect between the battery pack and the charger while charging and will shut off if the voltage spikes or is set to a higher amount of cells than the pack. It is a great safety feature.

Robert


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## wkstill (Mar 17, 2005)

I was doing a google search, and saw this post. I would like to say I have been running a LiPol 1500 2 cell, in my Nitro RC car & truck for over a year.. It runs three high torge metal servo's and i get around 10~15 hrs of racing out of one charge.. , I am going to modify my Electric Starter to use LiPol Next.. (Maybe just use the onboard Server pack to start the car from remote.. in case of engine shutdown, (Imagine them @ the track.. Truck die, flip on Ch X, Engine cranks, starts, turn off Ch X and resume racing :-]) I currently use a Great Plains Triton Charger.., also, the newer KoKam batterys are rated up to 64A discharge Rate. I have also Smoked Some LiPols, (smaller 1 cell 200mah packs) and the AMA warning is VERY VERY VERY true... The packs first Rapidly expand (and get very hot) This is why if you do choose to use them, build a strong inclosure for them, that is vented, and alows the cells to expand.. Any sign of the cell expanding destroy it and buy a new one.. (They say to cut open the battery and place in Salt water for several hours to destroy it).. going over there discharge rate is very bad idea... If you get a pack rated at 64A discharge, I would put a 30A fuse in place.. (my old RC Electric car had a 30Amp Fuse in the Speed Controller)


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## Craps (Mar 22, 2005)

The new 1/10th scale Pro Truck Class!

We race any 1/10th scale 2wd stadium truck with any motor/fuel system.

20 minute mains with 1 mandatory pit stop for the electrics for 5 seconds.

We have been getting around 30 minutes of non-stop runtime with the electrics for over a year now. The Thunder Power TP8000-2S4P 7.4 volt 8000 mah battery is mildly warm after a 20 minute race and can be fully recharged in around 1 hour.

There is currently over 10 of us electric Pro Truck racers here in the Carolinas with most only having 1 8000 mah li-po battery and 1 Astro Flight 109 charger that will charge at 8 amps. You only need 1 battery and 1 charger. You race the 5 minute qualifier after warming up for 3 minutes, plug in the battery to the charger, go turn marshal and almost by the time you are finished turn marshalling the battery is almost fully charged to race again.

With a big 8000 mah battery, you only need 1 battery and 1 charger. Practice for 5 to 10 minutes and plug up to charger while making changes on the truck. Just unplug from charger when you are ready (you do not have to wait for it to peak) and practice again. The Li-Po is real simple to use!

The future is here with li-pos and brushless systems!


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## Porksalot4L (Nov 4, 2002)

i dont know anything about li-poly but im curious. what is so great about them and not so great about them? would they make a stock,19t,or mod pan car go faster? how much are they right now? just keep it simple if possible cause im not to swift when it comes to this stuff. thanks

joe ivo


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## hankster (Jan 1, 1998)

Some good things off the top of my head:
A 2-cell pack is 7.4 volts so you will go faster.
More mAh in the same size.
The IR is lower so you have more accel.
They weigh half as much as NiMh packs.

Bad stuff is:
You need a special charger for them.
If charged improperly they can catch fire... but then NiMh cells can explode of improperly charged.

Cost for a 2-cell 4400mAh pack is about $100. While this might seem expensive, if you compare cost per mAh is comes out to about the same as a 6-cell GP3300 NiMh pack.


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