Is my LiPo dead?
 

Hi All,

I'm in need of some advice.

I have a set of Orion 5500mah saddle LiPos which for the last 12 months have worked fine, being used around 3 heats, twice a month. Always stored part charged (put away after final race of the day without charging or discharging).

The last couple of meetings, upon charging, the cells appear to be 0.1 volts apart. I always balance charge, but because the cells never get to the same voltage, I have to manually stop charging after around 1 hour. The more I used and recharged the LiPo last week (3 races in total), the closer the cells became, around 0.04 volts apart after 3 charges, but after leaving them for a week, they are 0.1 volts apart again.

Is this LiPo pack dead or can it be rejuvenated? I have used the pack as mentioned and have seen no drop in performance and don't particularly want to shell out on new cells.

Any info greatly appreciated.

Many thanks,

Alex

Have you tried them on a different charger? Could be that what is causing the issue. I've had the same cells not able to balance on one charger I had, when I swapped they were fine and equalled out very quickly.

Try charging them separately at 3.7V and see how different they are then.

make sure all the connections are good, a poor contact will see a voltage drop/variation which effects charge

I have experienced the same thing.. I put it down to the sensitivity of the charger as it can attempt to balance for several hours! It always succeeds in balancing but the wait can be disconcerting to say the least...

All in all, 1/10th of a volt is a small amount and unless you are more picky than a picky thing from planet picky, don't sweat it IMO... :D

Thanks for the help guys. I used it this weekend and didn't see any drop in performance. After each charge the cells got closer together, even finishing on the same voltage. I have now storage charged them and they're both sitting at 3.82V.

Will keep an eye on them and see how they go. I will try charging single cells next time as well to see how each cell performs. If I have no luck, I will try a different charger.

Thanks again guys :thumbsup:

Alex

Just out of interest what charger are you using?
My iMax B6 take forever to balance charge a few of my packs

As a few have mentioned, it could be a number of things. Bad contacts, bad charger measurements etc.

But if other batteries are ok with your charger setup, then that would indicate a fault with the pack itself. Its likely that the internal resistance of the cells are no longer matched, which means that when you discharge them they become unbalanced.

Its not a massive deal, as long as you are aware it happens and monitor it closely. try not to fully discharge the pack anymore, especially don't run it until the low voltage protection on your esc comes on.