I just bought myself a decent used Sager laptop and it came with a battery that only lasts about 40 minutes. I though it wouldn't be too hard to buy a cheap one on eBay or replace the cells in the pack. Turns out it's kinda hard to find this pack at a decent price (11.1v 7200mah), so I opened it up to find replacement cells.
I thought I'd check the voltage of the pack for fun (3s3p arrangement). I discharged the pack in the laptop and found out that each of the parallel combinations were at 3.8v! Not even down to the nominal voltage of the cells
. When I plugged the charger in, it took just a few minutes to bring them up to 4.18v
Does anyone know anything about modifying or resetting the protection chip? I think that is the main problem causing the severely limited capacity.