How out of balance is out of balance? - RC-Monster Forums

**How out of balance is out of balance? -** 06.09.2009, 10:02 AM

I have a pack that has a couple cells that are .03v different than others and one cell that is .23v different. Exactly how far is too far?

lincpimp · 06.09.2009, 10:35 AM

What brand of pack is it? The .03v cells are ok, that will easily balance out during the charge. The .23v cell sounds like it is having issues. You can try a slow .3 amp charge with a balancer hooked up to get the pack back into balance. Then let the pack sit for a day or so and see if it is self discharging on that low cell more than the other cells. If not give the pack a run and see if it comes off way out of balance again. .03v is not uncommon to see after a hard run. .23v is a bit much IMO.

BrianG · 06.09.2009, 10:36 AM

First of all, are you sure that is the right reading? Verify with a voltmeter to be sure. I have a couple of those little balancer/voltmeter deals that displays the voltage for each cell, but noticed there is always at least one cell that is "off". I know this and take it into account.

If it is indeed correct, 0.23v is quite a bit off. I would balance that while charging at 0.1A until it is balanced. 0.03v difference is fine.

06.09.2009, 10:38 AM

I am using a hyperion 0610i to read the numbers

BrianG · 10:41 AM

Do other packs show a similar discrepancy on that channel? I'm kinda leaning to a bad/overworked cell TBH. Voltage differences due to component tolerance usually isn't quite that high, especially on a quality charger system.

Arct1k · 06.09.2009, 11:27 AM

Also clean your connections on your taps - i've had bad reads with dirty taps

BrianG · 06.09.2009, 11:47 AM

^ +1. Which is why I take a spare male balance connector, remove the pins, hotglue the ends (where the wires exited) and use that to keep the dirt out of the connector when running:

blueb8llz · 06.09.2009, 01:38 PM

i had the same exact problems with my zippy 3s 2200 lipos. almost the same readings as yours too haha. if i did a normal charge, they were still badly unbalanced. but i did what linc suggested to slow charge at SUPER slow amp rate. it took like 5 hours just to charge that small pack, but it did balance out at the end of charge.
so i took it out for a run, the lipos had no punch, no top end. the lipo is done with. i tried charging it and running it again 10 more times just to make sure, and still no punch like it used to have.
so in mycase, i needed to get new lipos.
how are yours running?
is yours swollen anywhere?