So many to choose from…
My pick would be Bank of America for their illegal foreclosure practices which have ruined many families’ lives, and especially for their role in the subprime mortgage crisis which destabilized the entire global economy and which we are still trying to recover from. Everyone on the entire planet was impacted by the Great Recession.
So the battery is trash. Does it fully boot when you start it without the battery?
Did you replace the CMOS battery?
What does your multimeter tell you about the laptop battery?
https://pinoutdiagrams.com/battery/pinout-on-laptop-battery
The problem might be with dead/shorted cells in the battery or the charge controller in the battery.