Sudden Dell 700m problems with charging/battery

My dad has a 700m laptop and he got this back in 2005 or so.

The first battery that it came with had early issues with not being able to be charged past 50% or so and he got a replacement one under warranty that worked normally.

Fast forward to yesterday. He told me he was only getting about 1 hr on full charge and decided to try draining all the power out of the battery and then recharging it. He set the power options to always on and just left the laptop on running on batteries until it died.

A little later, it drained out and he plugged the AC cord back in to start charging the battery. He left it in for a good 5 hours or so and then he turned on the laptop w/ the AC cord still in. It booted up fine into windows and then he removed the AC cord and *ZAP*, computer went powerless.

We plugged the AC cord back in, booted into XP again and saw that the battery icon showed that it was charging and stuck at 95%. After more charging, it was still at 95%.

I googled a lot yesterday and couldn't find any solutions. I removed the battery many times, checked contact connections, etc and everything seemed ok. Power options were set back to max battery but that shouldn't have anything to do w/ the current situation.

We even took his old original battery and plugged that one in, charged it for an hour and XP said "unknown charge remaining" and once you unplug the AC it goes dead.

We have the latest BIOS revision if that makes a difference. Right now, we have a replacement battery on its way but still, what could be the problem here? I'm not 100% confident that the new battery will work here. Seems like maybe something is wrong w/ the AC adapter/charging portion, but XP shows the batt at 95% (that could be a false reading though).

Prior to all this, the laptop DID work w/ battery power only (just that it was only holding 1hr charge)

Cliffs:

1. Dad drained battery b/c it was only hold 1 hr max charge. Wanted to drain it completely and recharge.

2. After draining, laptop will only run on AC. Laptop will instantly die w/ AC cord unplugged.

3. Battery icon in XP shows 95% charged and stuck there.

4. Tried original old battery that came w/ laptop and didn't work either

5. Replacement battery coming in mail (could take awhile), but not confident that it will fix situation

6. Battery contacts/AC adapter contacts seem ok, A07 latest BIOS revision installed.

7. What could be the problem?

Thanks all.

 

Is the power connector for the AC loose? It is possible there is a problem in the circuits between the AC connector and the battery connector. I'd wait and see how the new battery goes before making any other guesses.