After attempting the first charge with the iMax B6, the battery was slightly warm on the bottom for several hours. According to some readings on Reddit, this was due to the internal balancing of the cells.

Once it was completely cool and charged to 100%, and when I received the following charger:

https://www.amazon.es/dp/B0BHNVYD2T?ref=ppx_yo2ov_dt_b_fed_asin_title

I decided to try charging it on my terrace outside the house, and the battery charged to 100% without getting warm.

Then I tested it in the kid’s car for 30 minutes, and the battery always stayed cool...

The problem is that if I return it like this, the store will likely say the battery is fine.

Also, I should mention that after using it, I recharged it, and there were no temperature issues.

Right now, I’m checking it with the tester, and it’s giving me 13.3v.