I was trying to move my Justock to 3.5 per cell and accidentally made it 3.5V My son ran his battery way down. Incidentally, it wasn't his new battery, it was mine.

Anyway, damage is done and it is what it is.

Will IR tell the whole story? In other words, if IR is good is the battery fine or can their be a divergence in the IR and performance?

Yes, IR will give you a very clear picture of the health of the individual cells. you'll know there's a problem when one of cells starts to increase IR... chances are the pack will start to swell at that point and then I would start shopping around for a replacement.

How does a esc with only main battery connection .monitor each cell.it can not it gives a total voltage.do what you want say what you want I know what I know.once you take a cell past 3.6 damage is done not fix unless you buy another battery

I have had cells go as low as 2.6V under rest immediately after a long run with LVC disabled... I boosted the pack in NiMH mode for about 30 sec to get the cells above 3.0V each then I finished the charge in LiPo mode. While I didn't have an IR meter at the time, I was able to get about 2 more months of use out of the pack before it started to swell and lose capacity/performance.


There is no hard set rule on how long a pack will last after discharge/charge but heat is the #1 cause for degradation of any pack and an IR meter can be used as gauge to give you a better idea of the health of your pack.

It doesn't monitor them in that way. It's just a multiplier. If you run 2s and have LVC set to 3.6V, then it will trigger when the ESC sees 7.2V. That can mean one is at 3.5 and the other at 3.7, or both are at 3.6... and so forth.

I don't know why you keep repeating that, but 3.6 is not the safety voltage level. If it was, ESCs wouldn't default to lower voltages.

He might be referring to resting voltage. A ~3.2V LVC cutoff under load can easily be in the 3.6V+ range after sitting awhile. When discussing low voltage its's always helpful to clarify which one is being used.

The IR wasn't much worse than normal on the pack last night so we will see. I went to put it on storage immediately following the undervolt situation and the icharger kept the charge rate low until it got above 3.0 and then it charged normally to 3.85 which is my storage voltage. I did run it in the main and it felt softer than the other packs. Possible more has to do with that it didn't get cycled before the main so the charge had been in it for a few hours. We'll see what happens, but I'm going to have my kid run it and see how it goes. I have 2 new packs already if either of these go south, which they will at some point.

Even then, the default resting discharge voltage on my iCharger is lower than 3.6 and most literature I can find online usually refers to 3.0V to 3.2V as the minimum safe voltage for a LiPo.

Besides, my Hobbywing telemetry tells me my load voltage regularly dips below cutoff voltage without triggering cutoff. It tries to ignore transient dips.

You mentioned that one pack was used for 10 races and cycled about 50-60 times. That would be you used that pack 5 or 6 times each race day. Are you allowing the pack to cool before you recharge it? Someone please correct me if I'm wrong, but charging your pack while it is still warm from driving it, can be bad for the battery.

What brand of batteries are they?

This is gonna sound really wrong to some people, but there's a ton of proof to back this up. Charging LiPo's is an endothermic reaction, so charging a warm LiPo actually has a cooling effect. If there is an internal short, a high charge current can make the pack go boom, but that's a different conversation.

There is nothing wrong with charging a warm LiPo. The problem lies with discharging a warm LiPo.

Charging your battery while warm from driving while harmful, is not nearly as bad as letting it go too low or not storaging it. I always charge at 40 amps, sometimes cycle it for qualifying and mains, my batteries tend to last about 1.5 years before the IR gets above 2.0 miliohms. At first sight of puff, the battery goes to disposal (I've seen a fire, luckily not mine but still not something I want). Consider how racers cycle their batteries at 40amps. This is to warm up the internals of the battery lowering the IR.

I know, that's what had me scratching my head when people told me it was to warm them up. Charging alone wont do it. Cycling, however, will warm them up, and that seems to be what people actually do... Charge, then discharge through a resistor bank and then charge again. It's the high current discharge cycle that warms them up.

These particular packs are Gens Ace packs for spec racing. I cycle them for races. Discharge to 3.5 per cell and then recharge. 50-60 includes some practice days. Most race days include 1-2 practice runs, 1 qualifier and 1 main.