Dell laptop dies when unplugged but the battery appears fully charged

Question

To expand on what I mean, I checked the voltages of each cell in the battery pack and they each read about 4.0v ea (6 green Li-ion cells in a 11.1v 53WH battery) and the total voltage reads 12.4v.

At this point I'm thinking that the problem lie in how the laptop uses the battery though I'm not sure how to test this.

Once the power cable is unplugged, the laptop will remain on but the built in battery light turns orange. It abruptly shuts down after about 10 minutes so it is using the battery to an extent.

This is a Dell Inspiron 6400.

Solution

If the battery voltage shows it really has been depleted when the indicator turns orange, than it would seem that the battery is at the end of its life. The amp hour rating of laptop batteries decrease with each charge/discharge cycle, and it seems that this battery has reached the point of being measured in "amp minutes". Sadly, sometimes a battery will reach this point rather suddenly. And when it does, its time to bite the bullet and get a new battery.

Comments

[Enigma]

A test of the battery will prove this either correct or incorrect. I just have to rig up something that's burn 12v. I've revived many "dead" batteries and just because the computer has an orange light doesn't mean the battery is toast.

[Enigma]

Li-ion's have very good memory management. The batteries your referring to are Ni-Cad's which are crap for memory management. $40 isn't exactly dirt cheap and free is obviously better if the battery is revivable (if it is in fact dead which remains to be seen).

[jdh]

Good point. In some cases, the laptop is estimating the future life based on that battery id's history and discharge rate. If there is an error, in that history, the laptop's history settings can be reset thru "recalibrate" options potentially available with that laptop.

[Kien]

it is cheap compared to what the originally manufacture price :)

[Enigma]

I'll look into the bios settings for that. It's running Ubuntu so no windows functions would be possible.

[Enigma]

The battery was in a state that it couldn't be charged via the laptop charger. It still holds charge and I have revived it somewhat but it's life is short. Got a new battery for $16 on amazon.