Lipo charging

[michael]

Charged my new core Lipo 3250 battery for first time using the core udc 20 charger all very straight forward until i tried to charge it at club meeting after running a few heats with it. The charger came up with an error msg telling me one of cells was low i think. Not sure what i was doing wrong using same volts and charge suggested as when first charged,can anyone help .

[3975dave]

Did you top it up betwwen those few heats??

[michael]

No i did not top it up i suppose thats what i was trying to do but not sure what is correct voltage and charge rate.

[3975dave]

A 3250 lipo battery run for a few heats (i'm guessing 5 min heats?) could well have gone below its minimum safe voltage. Therefore some chargers wont re-charge it. You can get it back but i'm not sure how. Mark Christopher may know how to do it.

[bald eagle]

If you have let the lipo pack go below 6volts, then chances are the cells wil now be damaged. Try charging it without the balance lead connected. Max voltage should be 8.4 v when fully charged.Try charge rate 3.2amps, see how you go.

[michael]

Thats right 5 min heats 4 of them and car was stil running ok not dying or running slow. Will put battery on charger to read msg again.

[3975dave]

Thats pushing it to the limit I would say dude. I always topped up my Trak Power 3200s every run just to be safe. Takes away the guessing.

[michael]

Thanks for all the replys, you live and learn. The charger reads low cell, low voltage.

[3975dave]

Take it along to the club you race at and try it on other chargers. Some are better than others at bringing it back. It may not be damaged, just a bit low.

[michael]

Thanks you have been really helpful

[Si Coe]

Are you charging on auto? Because I have the same Lipo and charger, and it won't charge on auto-detect but works fine on manual.

Also, the Core UDC is unusually picky about pack voltage. I've had packs it won't charge but other chargers do.

[CJ Weaver]

Lipo batteries don't show any signs of "dumping" until they are completely dead. That is why having a Lipo shutoff is important when running Lipo batteries. If you don't run a shutoff, make sure you charge your Lipo batteries frequently throughout the day (just to be safe). I know some chargers will bypass the low voltage warnings and will put just enough charge into the pack to save it. As for performance, it may be effected slightly. Good luck! ;)

[jenski]

I have just had the same issue with my Core RC UDC-20. The li-po would charge ok of a normal charge, but if you connect the balance lead it shows one cell at 0.00v and the other at normal voltage e.g. 7.90v.

I contacted Schumacher and they said that it was likely to be the balance part of the charger had failed. I sent it back and was charged £15 as they said that I had shorted the balance lead (which is impossible with Demon lipo's as the connector can only go in one way).

If your charger does the same get it sent off. You never know they could fix it for free.