The usual trick we use is to make sure the machine completely discharges on battery, then fully charge it, then fully discharge it. This supposedly resets the 'fuel gauges'.

Does it run on battery at all when you disconnect mains?

Does it run on mains only when the battery is out?


Also, are the pins making contact with the battery? They can sometimes get bent, though I'm not familiar with the layout of this model. I'm sure a friend of mine had an HP machine where the battery had a discharge switch on it - I don't suppose this one does, does it?

I'm not saying it is any of these things, but they're worth checking first before assuming a dud battery.

I am checking the contact in the morning. The laptop will not work at all on battery. They cystem seems to know the battery is there but registers it as totally uncharged and will not charge it. This is a brand new battery.

It could still be a dud, though.

On an established system , if the battery is simply taking zero charge we'd usually assume it was either the charging mechanism or the battery and deal with it accordingly (batteries not under warranty, of course).

Just a thought, was the supposedly dead, original battery doing the same thing? That might swing it towards the laptop itself rather than the battery.

yes the original battery was acting exactly the same way. the only difference is that the "fuel gauge" on the original battery shows it at zero charge

Mmmm. Makes you wonder, doesn't it?

I think it raises a big question mark over the laptop charging function. Can you get it tested at a store?

I have a Compaq Presario 2111 Laptop with the same problem. I thought that the battery had eventually ended it's life of over six years, although it had been used mainly on AC mains power and has never been used on Battery alone. The orange charging LED kept flashing and I had to reset the time and date every time I switched on. I assumed that the Main Battery had lost its charge and also this allowed the CMOS battery to run down. So I purchased a new replacement Laptop battery and fitted it. It made no difference, the charging LED kept flashing as before. I assume now that the actual charging circuit may be at fault. I sprayed contact cleaner into the connectors on the battery and onto the connector on the laptop as well, no change. Any ideas how to change the CMOS battery and faultfind the charging problem?
Thanks Leo
Best Wishes from The Emerald Isle
Brian
www.danceunlimited.org.uk

Same here, my Compaq Presario 12XL505 has a battery that does not charge, the lights are on but no charge, then this morning it has a completely black screen. I can hear the fan, the hard drive churning, but a blank scren. Thinking that my screen was gone, I connect my desktop monitor to it, still no screen. Everything worked perfectly yesterday, but today nothing.