Question

\A good while back, I purchased 4 Mystery 7.4v, 900 mAh lipos for my HBFP. I have been very pleased with them and have many, many flights with them. One of them however seems to be shot, as when I use it I get almost no lift with the heli. I have charged it 4 o5 5 times with the same result. But when I check the cell voltage, both cells read about 4.0 v after I try to use the batt. If the batt is shot, no problem as I have gotten great use out of it. Only paid about 8 bucks apiece for them.

My question is if the cells read 4.0v each, what would make the battery weak?

Just wondering. The other 3 are OK.

Donnie D

It's not uncommon when a battery fails that it will show an acceptable voltage when it isn't under load. When the battery is put under load it can't supply the current. If you were to measure the voltage while the battery is under load it would measure low voltage. Why it happens could be many things. As the cells age they age at different rates and that can cause bat. pack problems.

FWIW, Curt

Thanks Curt. That explaines it. I guess it's time to get rid of that batt. But like I said, I can't complain. I've gotten a lot of use out of it for less than 8 bucks. I highly recommend these batterys.

Donnie D