Another thing is trackpower batteries don't use very durable cells. I've had 5 trackpower packs over the last year or so and they always swell up. Even with proper usage and storage. Vant batteries, Fantom batteries, smc batteries, LRP, venom... these are all good packs with very durable cells inside. They usually need to be mis treated for a long time before they start showing signs of fatigue and start to fail.

Personally I wouldn't use the puffed battery because the batteries are cheaper than the car with electronics. Look at it this way. The battery is cheap compared to replacing everything if it were to go wrong.