New Guy with a New Truck

Originally Posted by Steeni

Here's my tip: Charge that pack with only 0.1 C. That means if your pack is rated at 5000 mAh, then go charge the faulty pack with only 0.5 A instead of the 5A you would normally use. That way it would take about 10 hours to fully load your pack but it leaves your balancer with plenty of time to balance your cells out. Rince and repeat and after 3-4 times charging it that way your cells should be good enough to be charged normaly again.

Hey guys thanks for all the tips. ill have to try those pinions next. truth be told im hoping the stock one hangs on cause i like the way its geared as is, but stuff always breaks. Im gonna take your advice on charging it at .1C but will it be ok unattended? i dont know if i could sit there for 10 hours lol. 30 mins is one thing. by rinse do you mean run the pack in the truck? before i charge the pack at .1c should i maybe put the pack to storage mode? Once again i appreciate the input you guys do know your stuff. and if the lipo is done for ill just order some more. maybe 3 this time and hope for all good ones and side line the problem pack.

[Steeni]

Voltage measurement in such devices typically has a precision of +/- 5 %.
For 4.2 V that means +/- 0.21 V. So seeing 4.4 V on a cell is perfectly possible.

If you read the instructions on some of the battery packs, you'll find out, that most manufacturers of quality cells have warnings regarding this issue, since Kathodes of Lipo cells tend to corrode faster when applying to high voltage.

It is true that, even an entry lvl modern electronic loader will cut off a cell that's going to high in voltage, but the described problem may lead to an increased difference in internal resistance of the cells, only making the problem of an unbalanced pack even worse.

All that theory means that you have to get your packs balanced, or the problem will get worse and the method described in my first post above is a nice and easy way get things balanced again.

"Im gonna take your advice on charging it at .1C but will it be ok unattended? i dont know if i could sit there for 10 hours lol. 30 mins is one thing. by rinse do you mean run the pack in the truck? before i charge the pack at .1c should i maybe put the pack to storage mode? Once again i appreciate the input you guys do know your stuff. and if the lipo is done for ill just order some more. maybe 3 this time and hope for all good ones and side line the problem pack."

Indeed run your pack in your truck after loading it, after all you want to see if it can handle the power output you need. The desribed method for loadbalancing your packs with 0.1C is safe, even when overcharging, at least when using new generation cells, which will not explode and/or take fire with this low charging current. But in the unlikly event of overcharging 1 or more cells for a long time, they will corrode and increase their inner resistance to the point that they will be unusuable. This will only occur if at least 1 cell was in that state before you tried to load the pack, so no loss there.

[simplechamp]

Originally Posted by 88gtanotchback

A few questions i have tho since im fresh to this electric business is this.
1) why is it that when i charge one of my packs one cell is only 4.05v and the other is at 4.2 (it will climb higher then that if i dont shut it down but i stop the charge at 4.2v. I tried taking the pack down buy putting it into "storage mode" then recharged it tonight and still got those numbers. its on balance charge too. The other pack charged up to 4.2V on each cell perfectly. stayed balanced the whole time. i just want to make sure nothing is going to go wrong to cause big troubles. thanks guys and i look forward to scouring your forums for knowledge.

That sounds like your pack possibly has a bad cell. Everyone seems to be suggesting the charger is the problem, but if it can balance your other pack to 4.2v on both cells then it sounds like the charger is fine.

Keep and eye on the cells, especially the one that isn't holding a charge (check all the cells with a digital multimeter). If the one cell stays at 4.05v and won't charge any higher then you most likely have a bad cell. Not much you can do to fix a bad cell unfortunately.

I run the same 30C 2s hardcase Zippy lipos as you and they are great. The only issue with buying from HC is service and support. It doesn't make sense to send anything back to them for repair/replacement. By the time you pay for the shipping you're better off buying a new pack.

[_dV]

88gtanotchback, are those Maximizer wheels? Are they normal or 1/2 offset? What adapters did you use to fit them to the Flux?

no adapters needed. they are the 1/2 inch offset and yes they are maximizer's. great product!