I would suggest that all the indications are that the battery is no longer servicable. The specification will give you expected battery usuable time with a brand new fully charged battery. I do not think that there are is any that you can obtain the information you require without making internal modifications.
very rechargeble batt has a limited time life, eveytime you leave a batt in a laptop while using the mains and switch of the batt trickl charges back the slight discharge that goes on but when doing so counts it as a full charge. To look after batt if you dont really use batt power, fully charge, take it off and at least once a month put batt back use only batt run it down charge it back and take off again. As to wilham's post for rejuveated batts i cant help there as i only buy brand new for the piece of mind and warranty.
It came as a shock to find the battery in my Sharp was not listed by most suppliers. It was said in one forum all GP10-CH models were sold only by PCWorld/Dixons group, and also that replacement batts cost more than £200.