Dell G3 3779 laptop - limit cpu in bios to 90-99%

[steffabc]

Hi
Can anyone help me to limit the cpu in dell bios of g3 3779 laptop to 90-99% ? The laptop has a problem and it will connect/disconnect continuously from AC adaptor/charging when CPU is being "used" at 100% (even if not 100% sometime). I've done everything to find the fault but I think something is wrong with the motherboard and once I set 90% max cpu performance in power settings in win10, no more problems, I then upped the limit to 99% and still worked perfectly (tested with prime95), if I max it to 100% cpu performance it does again but once I set 99% even with prime95 the battery is charging/no more disconnection issues (I replaced the battery but same issue)
I noticed the connecting/disconnection from charging once in bios as well if I restart the laptop right after being used at 100% for a bit then go to bios. If I reinstall windows I will have to set again the cpu limit to 99% in windows but if I do it in bios it will be safer
There is no setting in bios as with most dell devices to play with cpu mhz/voltage etc. Is there any way to limit the cpu in bios by a mod/hack ?
Thank you very much