Battery & diagnostics errors as well as high kernal_task process

In my case it was clearly a battery issue. There were not many cycles left... anyways I didn't change the battery yet, I kept the laptop plugged to the power supply and this issue disappeared. I know that the time is ticking though....

Hi again! I changed the battery, did a SMC Reset but the issue is still present...diagnostics gives me back the same messages (pfm006 and ppn001). I finished calibrating the battery in the meantime, but I really don't know now how could I solve this.

Here the pics of coconut battery and iStat...

Disk Utility reported the ssd is fine, but I always keep seeing that keemel_task that is eating CPU.

Anyways many thanks indeed for any lead...🙏🙏