Imbalance/Overcharge question

[bcflyer]

Picked up my PL6 this afternoon. Got it figured out to charge and it's an awesome unit. Lots of information at your finger tips while charging. Had the battery start out at a range of 3.7-3.83. Currently sitting at exactly 4.09 per cell dead on. we'll see where it ends at. Checking the Thunder Power charger throughout a charge it was no where near balanced. This one is dead on so far. Mind you it may have been working with a not so good battery too. learning curve for sure.

[bcflyer]

The PL6 has been working away for 4 hours now. It started out slick and balanced the battery perfectly from 3.8 up to about 4.11. Then the balance went out of whack around .1(around 3 hours) and got actually quite warm/close to hot.
It stayed there for a bit and when it got to 4.12 it cooled off to just warm and stayed there(temp and balance).
Thing is the balance is dead on again from there on, currently at 4.14 all cells but the thing that baffles me is the charger says there is 3245 mah put in so far. The battery is a 2700mah. What's that? Is this the charger doing the balance? I noticed some cells being lowered in voltage when they started to get to capacity. Are these mah taken out accounted for in this total(3245)
Anyways, it seems to be balanced perfectly, currently at 4.15v/cell and still trickling in.

[Gregor99]

I suspect what is happening is the mah being put back in does not deduct the current that is being bypassed for balancing. Although those number seem unusually different. What was the starting voltage? W

What charge rate are you using? Scroll through the screens and see the charge rate the charger is actually delivering. If the cells are too far apart, the charger will detect this as an error condition and switch to safety charge mode which is only 500ma. Once the cells are back in balance you can restart the charge and it will go back up to the set rate.

Also, the Powerlabs start balancing when the first cell hits 3.8v. Before that, the cells may be out of whack.

Finally, this info may be helpful.


FAQ - Powerlab Quick Start Guide - Wiring modes, Supply Limits and 1s charging

[bcflyer]

I set the charge at 1amp. I did notice it was delivering 1.3 a few times I scrolled through the various screens.
Voltage started out 3.7 - 3.83 before hooking it up to charge and quickly balanced out.
There were no error events during the charge.
The battery did get quite hot though during the charge and from what I thought, this is not normal, especially at 1 amp charge? Lots to learn

[Gregor99]

No its not normal for a pack to get being charged a very low rate. Did you happen do notice the IR readings on the cells?

[RedOctobyr]

The hot thing caught my eye as well, bcflyer. I've never noticed a pack getting warm during a charge, even when I deliberately imbalanced them first. That seems rather odd to me. There's not much current flowing, so why should it get warm at 1A? It makes me concerned over what might happen at 50A.

As Greg said, I'd definitely check the IRs. Maybe that will help better understand the situation.

Talking to ThunderPower still may be a good idea, even if the IRs don't raise an obvious red flag. The pack getting quite warm during a 1A charge is not normal.

[bcflyer]

Thanks you guys. The getting hot thing was the first charge on the PL6 set at 1.0 amp charge. I did notice it was putting out 1.3 at times. The IR while charging was a consistent 4.3-5.4 read on the charger display.
And yes it did get quite warm, to the point where when you pick it up you say "geez, that's getting kinda warm?" I didn't thinkit was normal at all either. But it did cool off somewhat at 4.15 and was good after that. It balanced out really good on the charge.

I did a 6 minute hover to drain it off and it came out at .15 difference high to low cell. Put it on the charger and set it at 5 amp charge and it charged up in 40 minutes and never got warm at all and balanced out great.

I put it on a regenerative discharge and that went well too, all ended at 3.84-3.87V.

I don't know, the getting hot at 1 amp had me worried but things were in a safe spot so I said do or die and it lived. I don't get it. The IR isn't bad either from what I have looked at. But the IR is relative to varying factors as well. All voltages are right on when compared with a good quality DVM.

I will take your advice and contact Thunder Power and see what they have to say about things. kind of weird.

[bcflyer]

Found my notes on the charge after the hover. 1687 mah in. 1-6 cells balanced at 4.19V. IR 5.5-9.4