# Very short run time after charging batteries. What do I do?



## mako (Sep 17, 2001)

Last night I used my intellipeak charger to discharge the 3000 nimh batteries. The charger discharged to about 6.5 volts. Then it automatically charged them, I charged them at 5 amps. Today when using them they ran good, got 15 to 20 minutes out of them. Then I let them cool about 2 hours after use and recharged them at 5 amps, they charged quickly in 10 minutes or less. After being charged again the batteries only lasted 1 minute before losing their charge. What am I doing wrong? These are new batteries with only 6 runs on them in the Emaxx. Previously I was charging them at 3 amps and they ran okay I thought the 5 amp charge would be fine. Which it was after discharging them first!
Thanks.


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## The Jet (Sep 25, 2001)

5 amp charge is fine, what probably happened is what's called a false peak. The battery will sometimes fluctuate(sp?) in voltage and cause the charger to think the battery is fully charged then stop charging. If you suspect a short charge time, feel the battery, if it's warm, it's charged. If it's cold, it false peaked just go ahead an hit charge again. Check your voltage while charging, I believe a 6 cell pack will peak around 9 volts.

Later, Bret


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## mako (Sep 17, 2001)

The packs I have are peaking at about 8.5, is this decent?


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## The Jet (Sep 25, 2001)

It's been awhile since I cycled 6 cell packs, but I believe that's a bit low. Are they warm when they peak??? 140 degrees is about ideal for a peak.

Later, Bret


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## mako (Sep 17, 2001)

They are warm after peaking. I just charged a set of 2 batteries they were peaked at 8.5 my son used them and got a short run time about 3 minutes. I tried discharging another set then peak charged them and they too peaked at 8.5. But the runtime was a good 20 minutes. Do these batteries need conditioning or cycling? I'm totally new to rc and really appreciate the input. And if they do need conditioning or cycling what is the best thing to do? 

 Thanks, Dave.


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## The Jet (Sep 25, 2001)

Dave, I thought (Hoped) someone else would chime in by now because when it comes to screwed up batteries, I just buy new ones, and don't bother trying to revive anything. I'm bad that way.
You should cycle them on a GFX or some other hi-end charger, that will give you a better idea as to what is going on.
*TQCELLS* has plenty of cells on hand :thumbsup: .

Later, Bret


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## patcollins (Sep 29, 2001)

The actual value that batteries peak at means nothing. Batteries dont work good sometimes, then dont work good and then work good again they just dont work that way. 

If they are discharged completely before charging first make sure they are at room temperature before you charge them again. If they are hot when you stick them on the charger they are going to fool your charger when they start to cool. If you know the batteries are completely discharged get a time on how long they take and each time you charge them they should take roughly that same amount of time if you charge them at the same rate all the time. 

When in doubt unless they are hot just hit the button again. I don't know very much about your charger but it sounds like the peak threshold needs to be bumped up just a little. Try 6mv per cell as a threshold I have always had good luck with that for NiMH cells.


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## mako (Sep 17, 2001)

Thanks for the replies greatly appreciated. These are new batteries, I just put in and started using. I don't know how to cycle. What exactly do I need to do to cycle them? I'm gonna charge them tomorrow. Pat what is the peak threshold? And what do you mean 6mv per cell? Is that the rate I'm charging at? If so is it good to bump it up to 7? Also I let them cool to room temp for about 2 hours before charging. Sorry total newbie here. 
Thanks.


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## Z-Main Loser (Nov 17, 2004)

I race 6 cell stock so I'm familiar with 6 cell packs. A new pack of 3300's should peak around 9 to 9.10. 3000's should peak the same. If the packs peak out below that but are warm they should have a full charge. The more cycles or runs you put on them the higher they will peak. Anything over 10 is time for new packs. For racing that is. The peak threshold is how far the volts drop after peak. If your pack peaks out at 9.05 then you'd want the charge to shut off at 8.99. Using Pat's 6 mv. What amps does your charger discharge at? 3000 should get about 500 seconds of runtime discharged at 20 amps fully charged. Cycle them by charging them and immediately discharge them and see how much time it takes to fully discharge them down to 5.4 volts. I might be wrong on the runtime though but I think its close. Anyone with matched 3000's could help better on that one.


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## mako (Sep 17, 2001)

My charger discharges at 1 amp fixed. If I understand this correctly the packs are peaking at about 8.50 volts and then go down to about 8.35 volts. So is 15 mv my peak threshold? If I can only discharge them at 1 amp is this a problem?


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## patcollins (Sep 29, 2001)

Yes you want to discharge at a minimum 20 amps and preferably 30 if you are a racer.


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## katf1sh (Jan 17, 2002)

the worlds best r/c investment is a quality charger. 150.00 will buy you a lrp charger or a pit bull charger...the best investment is a used turbo charger like a turbo 30 for 150.00 would be great! quality chargers realy hold there resale value in case you decide the hobby is not for you and your son. a quality charger will save you millons in frustration alone,lol. pit bull charger, lrp charger or a turbo 30,35 or gfx...only chargers i would fool with....


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## patcollins (Sep 29, 2001)

The Novak millenium is also a very good charger, dont forget it


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## The Jet (Sep 25, 2001)

patcollins said:


> The actual value that batteries peak at means nothing. .


Really??? I use the peak voltage all the time to see if I'm going to make it in time for my heat. I KNOW my packs peak right at 6 volts, so if the pack is at 5.98 I know I'm close...So you see, it DOES mean something  .
Later, Bret


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## mako (Sep 17, 2001)

This is the e-mail I got from the battery company:

Dear David:

Charging current of 5mA is too high for the 7.2V 3000mAh Batteries. These are not fast charging batteries. There are chemistry limited reactions need to take place and take time to have the charge fully built up. We recommend you charge the battery with 1mA current, and this should give your battery packs good performance.

Please let us know the results of charging with 1 mA current.

Thanks
Customer Service


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## patcollins (Sep 29, 2001)

1mA? That can't be right, even this little 150 mAh 9volt battery I got here can take 20 mA charge current. Sounds like the person that wrote this has no idea what they are talking about. 

At that rate your battery would take 3000 hours to charge.


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## Z-Main Loser (Nov 17, 2004)

What kind of batteries are they? GP and Sanyo all have the charge rate and time on the cells something like 3300 mah for 15 hours or something like that but everyone including matchers charge at 5 to 6 amps. I think the battery company is covering themselves in case of an accident with the cells.


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## mako (Sep 17, 2001)

The batteries are from All-batteries.com they are called Tenergy batteries. I bought 6 packs for about $90.00 delivered, so at least I'm not screwing up high quality and expensive packs. I did alot of research before buying the Emaxx, I am very pleased with the truck and my son loves it. We are just dissapointed in the battery runtime we are getting. He is sometimes only getting 1 to 3 minutes just playing in the yard and the dirt without high speed running and I even told him to keep it in first gear to save on the battery run time. I also went with some suggestions from here and bought 2 Duratrax Intellipeak Pulse Chargers. I realize these are entry level chargers, the chargers charge fine but they only discharge at 1 amp max. Now I realize I need to discharge at 20 amps so am thinking about a bulb discharger. Also the chargers only discharge down to about 6.8 volts before gooing into charge mode automatically, they are supposed to have a fixed cutoff discharge of 2.60 volts before going into charge mode, so I don't know what is up with that. So I can't get the charger to discharge to 5.40 volts in order to cycle them. I've been experimenting and the best runtimes I got was when I discharged to 6.80 and then peak charged them at 4 or 5 volts, was 20 minutes. From what I understand with nimh packs you should be able to use them for even a couple minutes then peak charge them and they will still give the full run time. I would be thrilled to get 15 minutes runtime which shouldn't be too much to ask for especially when most of my sons driving is slow dirt riding and rock climbing and not all out drag racing.
Sorry for the long post, but I just wanted to point out exactly what I have here. 

Please any input is much appreciated as I'm going nuts trying to figure this all out!
Thanks, Dave.


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## tommckay (Sep 26, 2001)

he Tenergy Cells are probably the issue, they may only like charging at 1 amp for long periods of time. Sounds a little funky to me, but I've never seen a Tenergy cell let alone had any expierience with them. 

I would say you may have some bad packs. Unfortuneately $15 packs are not usually that reliable. If you can, set up a bulb discharger of 10 1157 bulbs and cycle the packs a couple times while timing the charge and discharge times. Remember to disconnect the bulbs when the lights dim noticeably. You will find any weak packs and can weed them out, the E-Maxx will only give maximum performance when 2 like packs are installed. So if you put in 1 good pack and 1 dog pack, it will only perform as good as the dog pack will allow it. Sounds like the time you got 20 minutes out of it you had 2 good packs, you may have a dud or 2 out of your 6 packs. That's the downfall of buying cells from discount battery stores.

Try buying at least 1 pair of quality cells (like GP or Sanyo) from a matcher, you don't need "high zoot" race packs, a 1.16v pack will do you fine. Check http://www.promatchracing.com/main.htm for their specials, in December they had 6 cell Sanyo 3000 NiMh stick packs for 19.99 a pack. Since you have an E-Maxx I recommend buying in pairs.


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## OvalmanPA (Mar 21, 2000)

Yep, I'm guessing your batteries are the culprit. They sound a lot like the CHEAP batteries I got from batteryspace.com. They are "supposed" to be 3000s but first charge/discharge at 5 amps/20 amp discharge came out WAY below 3000 mah. They are closer to 2000s than 3000s. The ONLY way I could get them to come close to what they are "rated" as was to rebuild them and put them on discharge trays before charging. The company offered to refund my money but the way I figured it by the time I pay shipping back to them I might just as well bite the bullett and say the heck with it. I did run them all last off road season in my EMaxx and could get 5 minutes out of them but much beyond that was questionable and talk about NO punch.


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## mako (Sep 17, 2001)

I charged all 6 packs last night, here are the results:

2 packs discharged and then charged at 1amp gave 10 minutes runtime.
2 packs discharged and then charged at 3amp gave 17 minutes runtime.
2 packs run low using the Emaxx, then charged at 3 amp gave 17 minutes runtime. 

My son driving some racing, some jumping and climbing, basically all around use. I guess this isn't too bad for these packs.

Next time I'll listen to Hankster and others and go for the maxamps gp 3300's.


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## tommckay (Sep 26, 2001)

Yeah, those run times don't seem so bad. I only get about 6.5-7 minutes on my race 3300's in my maxx, but then again I race it and am hammering pretty hard for 5 minutes!


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## The Jet (Sep 25, 2001)

Sometimes I only get 3.45 out of my brand new 3300's :devil: .
Modified racing is so cool  .

Later, Bret


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## kyoshojoe (Oct 14, 2004)

If you are looking for some good basher batteries. You can always jump over to the swap and sell forum. There are always racers looking to dump off their "less than the best" batteries for great prices and for the most part the batteries are pretty great still. They just aren't in the top 1% anymore 

I'm running my Emaxx with some gp3300's and it's a smoking torquey machine ))


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