compaq laptop battery reads 100% wrongly

hi guys!
i have a compaq laptop 2111AP bought in 2004; its battery failed within one year and was replaced under guarantee; then i didnot renew the warranty; the second battery i used very sparingly and most of the time the machine was plugged in mains with or without battey;

last month the L-shaped power connector got damaged as i kept the laptop on ground and it loosened the jack in the mobo; i opened the laptop and did a resoldering job; on reconnection the machine works both on battery and mains; but there are two issues:

1) the battery (lightning) indicator on the casing doesnot indicate- neither amber nor green;
2) when the windows is started, the systray indicates correctly battery present or absent or when the machine is on mains; BUT WHEN THE BATTERY IS PRESENT IT ALWAYS READS 100% ; IT STARTS READING LESSER VALUES SAY 90% WHEN THE BATTERY ACTUALLY GOES BELOW 25% ( THIS I CHECKED FROM THE FUEL GAUGE ON ON THE SIDE OF THE BATTERY PACK)i thought the battery requires calibration and left the machine on battery totally and did a complete recharge; on full recharge it states 100% charged battery time of 23hrs 45 minutes!

any views or help?

regards

 

I also have Compaq laptop for years and the battery also failed soon after i bought it. I have to have it plugged in the entire time im on the laptop. So i recognize your problem. I don't know how to fix it.

 

Unfortunately it's not uncommon for batteries to go bad after a year of use. My old HP zd7000 battery only lasts about 5 minutes even though it reports 100% charge, I have to keep it on AC power all the time. Most batteries only last 12-18 months of constant use.

Really the only way to keep a battery from wearing out is to leave it out of the laptop. Even plugged in all the time you can wear out your battery.

 

Most Li-ion batteries have limited shell live, that starts when build, so no matter what you do your battery is gonna fail sooner o a little later, doesn't matter if is the laptop plugged with the battery or not. Li-on batteries like to charged all the time, don't try to empty them, they don't like to be empty bellow certain point. If you want to store a Li-ion battery do it with a 50% or 60% full, but not totally full or empty. But remember that it is still wearing...

 

Why not to make a switch at the back of the laptop disconnecting the battery terminals when on AC-Power? This might hit battery companies pockets, but this might save battery life and finally, the environment...Right, who cares about it anyway...

 

hi guys!
thanks for the comments regarding short battery life; yes i know keeping the battery removed and unused is the only way to extend the life thought it will still lose power;

but my issue was different; the windows xp power monitor starts showing the battery at 100% when the battery is really less than 25%; and the battery gets charged and when charged "fully" (i mean when its fuel gauge goes to 100%) the battery monitor reads still 100% but the available time indicator goes crazy (it reads 26 hrs!)

what i want to know is how the xp gets the power monitor info? from the battery smart indication or by some other means? how to make it read 25% when the fuel gauge is 25%;

regards
neelakantan

 

IC...unfortunately the older and most newer HP/Compaqs don't have a really good battery calibration utility (either within Windows or in the BIOS). I'd check for any software utilities in your start menu...my wife's old HP ze-series actually had a little utility for battery calibration that was hidden in START->Accessories->System Tools. Another place to look is in your system's BIOS, on my Averatec it's in there.

Finally if you can't find anything...your only real option is to run the laptop on battery so that it fully discharges till it turns off, plug it in and fully charge, then unplug and discharge it again. This is supposedly one of the ways XP can adjust it's power guage, but in my experience even this method lacks any sort of real precision but it's all you got if theres no proper battery calibration utility.

 

wow i guess that explains why my compaq battery started messin up from the start. It only lasts 15 minutes or maybe less after 2 weeks with a new battery, so yea cant go anywhere with it