asus eee 900 question battery does not fully charg

[badbass]

I have an asus eee pc 900 I like to fool around with different linux distros . I dont want to test on a production environment. The problem is the battery wont hold a charge. Only charged to 20 percent. Is the battery bad? anyone else experience this.

[vector]

yes the battery health deteriorates after x amount of charges/discharges. all of my laptops have this issue. i have one that actually wont hold any charge at all anymore, the computer doesnt even recognize that it has a battery installed. and if you unplug it it instantly powers off. most laptop batteries will be good for approx 300 charges/dischares or so. bout a year or two. then they start to lose capacity. tools like acpi will show you your battery stats. for example this is mine right now using the command acpi -V

Battery 0: Full, 100%
Battery 0: design capacity 5661 mAh, last full capacity 2667 mAh = 47%
Adapter 0: on-line
Thermal 0: ok, 63.0 degrees C
Thermal 0: trip point 0 switches to mode critical at temperature 105.0 degrees C
Thermal 0: trip point 1 switches to mode passive at temperature 93.0 degrees C
Cooling 0: LCD 6 of 15
Cooling 1: LCD 6 of 15
Cooling 2: Processor 0 of 10
Cooling 3: Processor 0 of 10

you can see that the battery is designed to be 5661 mAh at 100% charge but it is only 2667 mAh at 100% charge approx 47% of what it used to be.

[Guest spazi]

If you need a new battery mugen power makes a few extreme ones :p

[Jason Cooper]

If it is the original battery then you should look to replace it whether it is working fine or not as its capacity is very low and the replacements can give you a significant boost.

If the battery appears to be working fine but your battery monitor program is showing that it only ever reaches 20% charage then one thing to be aware of with the eee PC 900 is that the battery monitor hardware doesn't return the standard mAH's left in the battery, instead the battery report the percentage left. This leaves most linux distros thinking that the battery is reporting that it only has 100mAH left when in fact it is reporting the it has 100% left. This throws most linux battery monitor programs and when I was using one on my old eee pc 900 I had to build it from source after altering the function that calculates the percentage left (It turned out top be a lot easier than it sounds as it just needed to return one of the parameters passed to it in the first place)