@promitheas Never heard about battery whitelists on T480. What BIOS version do you have?
Also there is a reset button in the bottom of the laptop near ThinkEngine controller: Power off the laptop, disconnect both batteries and CMOS and hold reset button for a minute.
Don't expect T480 with i7 to actually run 4 GHz all times when needed. Get an i5 model instead.
I have i5-8350U. The best frequencies I could get on heavy load are 3.5-3.6 GHz (dGPU heatsink + PTM7950). Still throttles but not so much.
T480 has excellent battery life with both 24 + 72Wh batteries. What was the main reason why I got it.
My laptop wasn't refurbished. I got it used without some parts - SSD and both batteries. Then I bought all parts by myself.
It could be cheaper to refurb it by yourself rather than by someone else.
@Jumuta Skulls just uses SeaBIOS as a payload, so it mush simpler.
However you can still try Libreboot, but you need to dump your firmware and extract binary files from it (like IME for example, and vgablob if you have Nvidia GPU)
@someoneFromInternet let me know if the issue will resolve after an update.