Thunder Power Pro-Race 4s1p 5000mAh 40c!

I've purchased and used the 2S & 3S 5000mAh packs.

Both packs are friggin nuts...the 2S was damn near the performance of a 3S pack. The 3S pack wasn't as close to a 4S, but it sure was close.

The only problem that I've observed is that the cells get out of balance a little quickly. Now I'm a real stickler for taking care of my packs. I usually don't let them discharge below 3.4v per cell and I try to keep their temps below 125F. When I charge them, I charge at a 1C rate with a balancer.

Even with this kind of care, though...the cells still get out of balance. Sometimes as much as .08 of a volt.

Great packs, deliver a crapload of power (make sure you beef up your drivetrain; most especially your diff cups) but IMHO for the price you pay for 'em, the cells shouldn't get out of balance so quickly.

Then again, that's just me. Perhaps I've been spoiled too much by my NeuEnergy packs.