BATTERY CHARGE / DISCHARGE PROBLEMS.

XPS 15 7590.  Service plan expired 18 January 2024.  Service tag <Private data removed from public view. DELL-Admin> 

I am wondering if you could give me some guidance on a battery issue with this laptop. The issue is starting off fully charged then after 2 hours approximately when battery is between 77% and 80% it just closes down and battery 0% flat. Plugged back into power it powers up after a couple of minutes with a push on the power button. Battery showes flat 0% and charging and over about an hour gets to 20% charged and showing about 3 hours to fully charged. Then soon after while still in low 20% all of a sudden jumps to show 100% fully charged. I wonder if possibly the battery is only charging 20%.

After awhile with this issue about 6 months back I purchased a genuine Dell battery exactly the same as the original and the same issue continued with the new battery.

Originally the laptop was Windows 10pro and then upgraded free to Windows 11pro.

As a last resort  I have done a clean install of the original Windows 10 pro OS and the same battery issue continues. I do not have another charger to try, could that be connected to this battery issue. Support Assist has not uncovered any battery issue.

Would appreciate if you could give me some information and things to check as  this is otherwise a laptop with some good life still left in it.

Thank you.