Charging Problem

[Jamie B4]

Wonder if you can help - seem to have an issue charging lipos.

Got a power pal charger from cml that i use to charge vampire saddle lipos from dms.

When racing and being scruteered my lipos are very low with regards to the 8.40v limit.

Been watching both and the charger seems to be dropping the ampage while not being at 8.40v, is this faulty or a setting on the charger

Is it the charger or lipos cos want to sort this out once and for all, have sent the charger back once to cml for a noisey fan but they did not rectify that.

Please help

[adon30]

By 'low' what voltage are you actually seeing? And are you charging to full capacity? I have a different charger from you and you can change the capacity stop point.
Are you charging from mains or 12v source?

If your not sure about the charger, find someone who's cells are charging to a higher voltage and see if yours will do the same on their charger.

One final question, how old (much use) are the cells?

[Jamie B4]

Charging from battery and mains.

When I say low voltage I mean 8.28/8.30 rather than 8.40v. When I put them on another charger they still need to be topped up. Lipos are about 6 months old and used for all events

Sure its nothing drastic but would like to make sure before new season starts

Not sure how these lipos are charged and balanced

[Jamie B4]

Also charging at 5amps and lipos are 5400mAh but charger can not go any higher

[sosidge]

You should also check the cell voltages with a seperate voltage tester, it's possible that the charger is reading the voltages incorrectly, if it is then it will probably need replacing.

Otherwise it sounds like the LiPo is well out of balance and that the charger is starting the balance process very early - ie one cell is at 3.7V but the other cell is only at 3.6V and will need a LOT of balancing to sort out.

I had this with a pack that had been over-discharged, after a few attempts at a charge and discharge I just could not get the voltages to balance and the pack was only fit for recycling.

You can try leaving the charger attached but it may take a LONG time for the cells to balance at 0.1A. Perhaps never. Or you can try a balanced discharge to 3V per cell, and then try charging again. If that still doesn't work, the pack may well be dead.

[tyreman]

Jamie

Check what the cell voltage is set to on the charger, as on mine i can change the pack volts in 0.1 incriments.
As most of the current chargers are all the same just rebranded.