What's wrong with this Lipo???

[solomon7]

It's TP 1320 3 cell.

It charges up to 4.20 on all 3 cells and peaks.

I plug it in the car and give it a few bursts. All is well.

Drive it a few feet and try to give it some throttle. It's like a 6cell Nimh!! Gutless.

I unhook it and Cell Spy it. All the cells are 4.16, but it runs like crap.

Took it home and it only took a couple minutes of balancing i.e. still fully charged.

I'm at a loss.

It's a couple years old but that shouldn't matter. It just started doing this out of nowhere.

Thoughts?

[JohnRobHolmes]

A couple of years does matter. Internal resistance slowly increases, and LiCo chemistry wears out on a shelf after about two years. Add on the time that it took from factory to your hands and you likely have an extra 6 to 12 months on the pack life.

Sounds like the IR is too high for you to use in your crawler. If you have something smaller, or another use for it you can get more value out of the pack. My suggestion is to get a new pack.

[solomon7]

That's what I feared, thanks John.

The weird thing is I bought 4 packs at the same time. The other 3 are runnin' strong. Oh well.

I've tried running this pack 3 times now with the same results.

Looks like it'll live out it's last days in a small jet boat.

[JohnRobHolmes]

Maybe that pack got beaten a little harder, or taken down to low voltage cutoff a few more times. Hard to say. I have a larger brick that I just discharged too far (18s 10ah), and two of the older cells gave up the ghost on me. All the other cells of similar age are fine, but those two just died on the spot.