Laptop battery recalibration

[dsio]

Ok, i have a bit of a problem here...

My laptop is a Compaq M300 Armada
P3 600
512MB sdram
80GB disk

The laptop is one of, if not the smallest proper laptop ever made. Its around 1.5cm thick, 11.3 inches diagonally and weighs in at 1.2KG.

The problem is the replacement battery for this thing costs around $300 in australia due to its compactness and complex power level reading system. I cant buy a $300 battery for a laptop thats only a P3, its just not worth it.

The battery used to give me around 2 hours per charge. Recently i loaned it to my brother who considers himself to be a bit of a genius. he went into power management and recalibrated the battery "for my benefit" thinking it would help.

It didn't.

I now get around 40 mins off a charge. I read a little into it, and you are meant to calibrate the battery once, then leave it forever, or until it asks to be recalibrated. Is there a way i could get it back to the state it was once in?

[Gizmo]

As batteries age, they lose capacity; that's just the nature of the beast. Unless it lost significant capacity as a result of the recalibration, there is probably rather little you can do. If your brother's 'recalibration' caused it to actually lose run time, then here's what I would try:

1) Discharge that battery completely. I mean stone dead. Run it in the laptop until the laptop refuses to use it. After that, if you can sus out the power terminals on the battery, then you should build an apparatus that will allow you to discharge the terminals through a resistor (something like a 100 ohm 5 watt would be dandy). Let it set that way for a couple of days.

2) Now go through the battery's calibration procedure.

[robbie]

What I did to bring back the battery life on my compaq laptop was to completely charge the battery and then pull the power cord and let the laptop run. Run it till it dies. Plug it back in and charge the bettery back up, unplug and let it run till it dies. Plug it in and charge it up, unplug and let it run till it dies..... plug in let it charge......... you get the idea.

This is called cycling the battery. This method worked out great for me as when I first did this the laptop wouldn't even stay on for 2 seconds........... after about 20 times (maybe more) of doing this I got it to stay on for about an hour. I think it took me just about all day to do this but....... it helps and it works.

One thing I did to help "speed up" the discharge process was to play a divx or a cd.
HTH
Rob

[dsio]

Yea, the battery went from 1 and a half hours before to 40 minutes now. Its a huge decrease. And it never seams to get more than 93% full, and then the power meter goes nuts. It drops to 30 minutes remaining, then works up to 45 minutes, then drops to less than 40% left, then stays at 40% for ages, then dies.