I appologize for not being very clear in my posting. All of those BIOSes do not need to be installed.
They do NOT have to be installed in order... but if the latest one will not install, go back to the next most recent... as your Thinkpad needs one critical update which all those listed do have... so if one duesn't install after you turn off the password, go back to the next one, such as 3.10 or 3.11.
The BIOS Updates are not for the operating system, but may allow something in XP work better... There are a large number of fixes in 3.12, and one or more affects WXP, while some affect VISTA.
Use a regular pencil eraser and clean the metal points that connect the battery to the Thinkpad... If that doesn't work, I am afraid you need service... i would send it back to IBM Lenovo Easy Serve. You might see if the warranty can be extended, as generally Lenovo does allow warranty extensions.
I am sorry to report that Thinkpad 3000 is not popular among Thinkpad users... and is one of the few without a positive history. Lenovo has had a lot of trouble with it... and mass marketing at Costco, CompUSA, OfficeDepot and the others did dhte rest. You might consider cutting your losses and getting a T42, T60, or T61.
I have only worked on one Thinkpad 3000, and that belongs to my daughter in law. You might consider joining Bill Morrow's thinkpad user group, or the Thinkpads
http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
or search for Bill Morrow's Thinkpad site.
You may have to do a clean install to get rid of the 10% error... if you do not have the disk set, you can buy it from Lenovo for under $50 including shipping.
I consider the battery charging as a serious one. If that Thinkpad has a Fujitsu drive, it is probably a good one.
The BIOS upgrade, if you can get one installed at 3.10 or higher may clear up a lot of problems.