laptop charging issue

[AmdEmAll]

This is a Compaq Presario 700z w/ windows xp

Works fine when plugged into A/C and says battery is 100% charged but if I unplug it, it will only stay on for a minute or so and then die. When I go to recharge it, it says charging and within a few minutes its at 100% again.

Ive replaced the battery with an ebay one and it does the same thing. Is it the battery, charging plug, or circuit board inside?

 

[AmdEmAll]

Ok this is odd, I unplugged it and wanted to see how long it stays on battery. It went from 100% to 0% in about 5 min but its been on for 18min now and its just beeping and at 0% battery power.. yet its still on wtf?

EDIT: It died at around 25 min, never seen it last this long.. odd.

 

[stargazr]

Are you using the correct AC pack?

Sometimes after prolonged use the jack where the AC pack plugs into become loose resulting in an intermittent connection.

 

[AmdEmAll]

Original AC Pack and the plug isnt loose at all.

 

[stargazr]

I would try to find another AC pack to try. It is strange though that it would power the unit but not charge the battery. That's usually a good test.

It is possible that the ebay battery is bad. I never had any luck with the cheaper ones, they don't seem to last.

What I don't understand is the battery meter is off so much.

 

[C1]

This sounds like the classic case of the third terminal of the power brick gone bad. Apparently Dell & Compaq use the third wire to as a reference to determine battery charge level. If you should decide to replace the power brick, then it needs to be an actual OEM brick (not a second source).

You can google for an explanation of what is going on. As I recall, Tomsharware featured a detailed analysis/discussion.

 

[AmdEmAll]

This is weird as hell. I keep charging it to 100% and then draining it and everytime I do this it stays on longer.

Got it up to 45min battery power right now. Been beeping at 0% for 10-20min lol

 

[C1]

Laptop Repair & Maintenance : How to Test a Laptop Battery
http://www.youtube.com/watch?v=JPq1lsMxDkI

Revive A Dead Laptop Battery
http://www.youtube.com/watch?v=LZwQu5gTOoI&feature=related

 

[AmdEmAll]

Laptop Repair & Maintenance : How to Test a Laptop Battery
http://www.youtube.com/watch?v=JPq1lsMxDkI

Revive A Dead Laptop Battery
http://www.youtube.com/watch?v=LZwQu5gTOoI&feature=related

Read the comments for that second video.. it kills Li-ION batteries and only works for Ni-Cd which are only found in really old laptops.

 

[C1]

Read the comments for that second video.. it kills Li-ION batteries and only works for Ni-Cd which are only found in really old laptops.

I wouldnt think so. Li-on batteries can be stored at -20 deg C

http://www.batteryspace.com/prod-specs/ICR18650NH-2200.pdf

The thing that F's them the most (quickly) is the combined effect of keeping them at full charge (few cycles) at high temperature.

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

 

[AmdEmAll]

So I had it charging all night and day and it just stayed on for 1 hour and 5 minutes haha.. so odd. It gets better and better like its relearning.