I have a 3yr old laptop, Acer 1810T olympic edition. Battery parameters, as written on the battery itself: 11.1V, 5.27Ah, 5600mAh, 63Wh. What's been happening lately is that it goes normally down to approximately 50% of the charge and then instantly down to 5%, and hibernates (Windows setting). If I bring it up, it shows 5%, which will last ~5-10 minutes and then die completely, until recharged.
I tried to burn-in using Aida64 (100% CPU usage) down to those 5% and then recharge to 100% several times - seems to have no impact on battery scale (same 50% -> 5% jump).
My BIOS does not support any sort of battery calibration.
Can I do something else about it? Is it enough evidence that I need to replace the battery?