Battery charged at 100%, but will not run from battery

I have a HP Pavilion 15-db0032na,

The battery states it is always charged at 100%, but without the power cable will turn off as it cannot run from it's own power.

After attempting the usual stuff (trying to calibrate it with bios and software etc) but getting nowhere as it cannot run from it's own power I have taken the battery out and tested the voltage of each cell. each cell should be 3.7v which usually they max out at 4.2v but noticed each cell at 4.3v.

I took some LED's and ran each cell to 4v and put the battery back into the laptop. The battery worked lovely for around 3 days, then the same issue crept up.

I assume the BMS on the battery is not functioning properly since the cells seem to be holding a charge, yet the laptop will not run from them.

Looking for a battery replacement and the batteries I find are 11.55v battery e.g.

HP HT03XL Battery

Yet the battery that is installed is a 11.4v which is shown in the install guides:

https://guide-images.cdn.ifixit.com/igi/...

Does anybody have any idea to get the battery working again or is it a lost cause?

Does anybody have any idea if the battery from ifixit would be compatible even though the voltages are different.

Any help would be appreciated.