I was bugged by this weird battery charging problem with my HP Pavilion Laptop for a past months. I started to notice this a few months back, when the power meter in the system tray did not show any movement whatsoever, even when plugged in and the battery was not 100% charged. In the earlier days of this problem, battery charging process used to get stuck somewhere around 85-90%. Rollover bubble on Vista’s Power Meter System Tray Icon used to say Plugged In, Not Charging…
A few days later, this percentage dropped further below to around 45-50%. Battery would simply refuse to start charging beyond that.
At this point, I started looking around net for some serious solutions for this problem and started trying them out.
Most of the results pointed to potential battery/charger problems, some suggested that it may be the problem with sockets or connectors. I even tried the trick of putting the battery in deep freez for some time, to cool it off. Though the freeze trick did some good, it still didnt allow my battery to charge all 100%
So for another month or so, I stuck with battery that would charge around anywhere between 50-70%. disconnecting the charger and plugging it back in used to give a charge of another percent or so, but even that trick didn’t always work and seemed to be very stupid thing to do repeatedly :p I kept going on with it till finally, a few days ago, the battery charging stopped around 24%. Which is when I decided to take my precious lappy to the people from whom I bought it.
The guys suggested me to try the following, before going further with a new battery and/or charger.

the process:

• Start the laptop, enter the bios settings.
• Put the plug in, start charging the laptop, until the “charging” indicator goes off.
• once that goes off, disconnect the laptop from the charger and let it drain itself off completely.
• once it’s drained, put the charger pin back in and start the machine
• again, enter bios settings and wait
• wait till the charging indicator led goes off again.
• repeat this charge-discharge process a couple of times more if you wish
• then restart and try booting into windows, see if the battery is fully charged or not. (it not, i guess, repeat the process , or go back to the lappy people….. this worked fine for me at the first time )

I also tried draining it down to around 87% and charging it back to 100% with success.
I’m happy with the result, thus, thought I should post it online
I’ll wait for a couple of days more and add a comment stating whether the problem reappears or not.

~Nac