Laptop will not charge its battery

[obi1007]

I have an old Compaq nc6400 laptop which simply will not charge its battery no matter what I do. I've tried 3 different batteries, so it's definitely not the battery causing the problem. The laptop is running Windows 8, and originally it said "plugged in, not charging." I did the fix where you uninstall the Microsoft ACPI-compliant drivers and restart, and now the "plugged in, not charging" message no longer shows up, but the problem is that the battery still doesn't charge past roughly 50% where it starts. All of the batteries I've tried have come somewhat pre-charged, and interestingly, if I unplug the AC adapter, the laptop will continue to run normally until the battery runs out of juice. If I start out with a new battery at 50%, and run it for a little while down to 40% and then plug it back in again, the battery will then just stay at 40%. It is then impossible to charge the battery back up again. This means that cycling the battery is out of the question as well. The laptop also runs just fine with no battery installed while plugged in using the AC adapter, so the AC adapter appears to be just fine. I've also updated the BIOS and tried running Ubuntu and Fedora on the computer, all at no avail. I'm literally willing to go in there with a soldering iron if need be. But, when I popped open the computer and took a look at the battery contacts on the motherboard and surrounding area, I saw no visible damage. At this point I'm just downright curious about what could possibly be wrong. The laptop can draw charge from the battery, but not charge it. It's almost definitely not a software issue, but no hardware seems to be damaged. Can anyone think of any other possibility/other things for me to check? Thanks in advance.

 

[JackNaylorPE]

Have you recalibrated the battery ?.... has to be done when installing new battery

Follow procedure here ... remember because you are calibrated on the old battery, you will never see 100%....so try charging overnight.... run it normally for 2 hours to let it cool down and then unplug and follow directions.

http://batterycare.net/en/guide.html

 

[obi1007]

Have you recalibrated the battery ?.... has to be done when installing new battery

Follow procedure here ... remember because you are calibrated on the old battery, you will never see 100%....so try charging overnight.... run it normally for 2 hours to let it cool down and then unplug and follow directions.

http://batterycare.net/en/guide.html

Thanks, but this doesn't work. After getting down to 5%, the battery will simply stay at 5% and not go up at all from there.

 

[JackNaylorPE]

You let it stay for 5+ hours unplugged after going into hibernation ? Another option is to leave on at BIOS till batter is completly dead.