Has anyone else seen this?  I have tried draining the battery, and recharging, but it just stops at 51%.  It says "Plugged in, not charging".

I take it back, it stopped at 52%, and says "Plugged in, not charging" again.

Sounds like the protection circuitry in the pack itself may be detecting something during charging and shutting down.  This can happen if the circuitry detects a large delta in voltages between cells in the pack.  A high self discharger within the pack can cause serious problems as well, and well designed protection circuitry will detect this and shut the packs ability to recharge down in order to protect you.

I would try a new battery pack.  This is where things get interesting.  You can dare to pay the 200-300% markup from the OEM or laptop maker.  Or you could, if the pack is not covered by any warranty at this point, carefully disassemble the battery pack and find out who's cells are being used, such as Sanyo, Panasonic, Sony, Molicel, etc.  You can then try and contact the manufacturer directly and try and buy a pack from them or the OEM pack manufacturer they provide cells to.

Having been the Sales rep and RMA specialist for Molicel I know this can be done with a couple of the companies if you have the time to do it.  Our cost on a pack purchased from a pack assembler we provided cells to was around $34.  I hear from end users that were being charged upwards of $200 for these packs.

Either way, good luck.

Cheers,
K

Fiius

Some places offer a "battery repack" service.  Its the exact same thing as kaninja describes, except someone else does it for you.

Contact stores that pretty much only deal with batteries and they might be able to help.  If they have a location near you, I think Batteries Plus (http://www.batteriesplus.com/) can help with a repack.

~Fus

I've seen some of these repacks....some good, some horrible.  I actually had one guy try and RMA a 6 year old pack with us.  Upon inspection the pack had obviously been roughly opened and taped back together.  Once we opened it we found our competitors cells inside.  The tabs weren't even welded to the cells but instead had an extremely horrid solder job which caused the failure.

Beware is all I have to say about repacks.  If the pack is the problem I recommend a new pack.

Cheers,
K

No, this is the original battery from about 2 years ago.  I have tried to maintain the battery properly by fully discharging it and recharging it periodically.  This issue is very recent, like since Christmas.  However It may have been going on since I reloaded with Win 7.

kaninja

sirmasterboy

The most effective and safest way to de-charge a laptop battery completely to attempt to re-calibrate is it to boot into the BIOS and let it sit until it just dies.

Definitely works, but I think Tweaked stated he completely drained the pack in his original post.

Just am idea.  Did you recently but a new battery for this laptop?  Is it possible this new battery has double the rated mAh of the old one?

Interesting idea.  Typically if the pack complies with the SMBus specification this "should" not happen.  However with so much counterfeit and black market packs coming out of China I wouldn't doubt this could be a possibility.

Cheers,
K

Yeah I doubt it but I only said it because I ran into this issue a few years ago when I bought a hi-cap battery for an old laptop and it stopped charging at the exact percent compared to the new increased mAh.