Researching BD Prochot / 0.39 GHz - battery might be the cause?

Hello there, I see there are many topics regarding BD prochot issue / CPU stuck at 0.39 / 0.79 GHz. Well, it happened to me, too. I thought it was a board issue (I have experimented with it a little so it wouldn´t be impossible that something is broken), but now I have a new board and immediately same issue. Well, worse, because on 11gen I could just disable BD prochot in Throttlestop, but on 12gen I can´t.

My findings: I am 99.9% positive that it´s the battery. When I disconnect it, BD prochot goes away immediately and I have not seen it once without battery connected.

Can it be that the battery is overheating? Is it possible to monitor the battery temperature? (I can´t see it in HWinfo).

It happens almost exclusively under load. I am using it in my 10" tablet - placed over the CPU, so that could cause overheating, although right now the tablet is disassembled and I put space between battery and CPU, so it is like 2cm away from it and it keeps happening.

My new board is actually covered by warranty, but I doubt the board is the issue, because if something happens on 2 boards and one battery and stops happening when I unplug the battery, it should be the battery. Now I just need to know if I need a new battery or just a way to keep it cool.