lipo balancing problem
 

I am having a weird problem with a fairly new FP 5s evo25 5000 pack. I have about 20 cycles on the pack and when charging after the last run I noticed that the charge time was twice the normal and that the cells were not balanced like usual.

I use a Hyperion EOS1210i charger and LBA10 Balancer both of which are working perfectly with my 2/3/4s packs. What appears to be happening is that the balancer is not dropping the highest voltage cells as normal but is instead just bouncing the high voltage around to the other cells.

I balance all packs during charging and have never had a problem. I'm thinking that I have had connection in the balancing leads on the pack start to come loose and are not providing a good connection perhaps? Has anyone seen this problem before or know what may be causing it or even a good way to test?

use the LBA10 to balance the pack in disconnection mode just to be safe. Once you get the cells back to even try charging them again. I would not charge the pack if you suspect that something is messed up with the wiring.
Do you have a voltmeter? You could manually check the voltage of each cell so you know where you are.

I have left the pack on the balancer in disconnect mode for many hours with no success. The difference between the lowest and highest charged cells seems to remain constant at @ .15v even after discharging to 3.6v per cell and then charging again. The lowest and highest cells do not remain constant and are completely random depending only on when the balancing is stopped.

That is a weird issue. I would check them again with a volt meter just to be sure, then maybe contact FP

Is it possible that the 5S balance harness is worn/defective? I had a similar but different problem that had me confused for several days...except my problem was a bad deans connector.

I agree it is rather odd and bothers me since I cannot think of a logical reason why this would happen.

I checked with a volt meter and it is consistent with the voltages shown on the charger and none of the cells seem to be shorted to each other. Aside from the cells being out of balance the pack seems healthy otherwise.

I left a message for FP support (I could not find a live person even an operator) so I'm hoping they call back sometime soon.

Now that may be a possibility. I am using one of the multi tap adapters for the balancer that has 2s - 6s taps all on one card. I will give that a check to see if it has gone bad.

... bad or dirty...

And BrianG is the winner with dirty... It looks like there was some build up in the deans connector possibly from the arc when connecting to the esc. I cleaned it up and it is now balancing properly.

I never would have guessed that would cause the balancer to act that way. Thank you everyone for your help!

Brian is always thinkin "dirty":lol:

http://i11.tinypic.com/8awmlxw.gif

Good to hear you got it resolved. I have the exact same charger/balancer setup, and that would have drove me nuts too. I certainly wouldn't have thought of that.

Sleeb

Finding dirt is always cheaper when it comes to lipos! Good job!