I have Dell Vostro 1520 . whenever i switch off the ac power supply , it shows battery critically low and hibernates . This happens how much ever the battery is charged .
This does not happen when i start the laptop on battery power .

Make sure you have at least kernel 2.6.35.10-74:

- Backport the ACPI battery notification patch (#656738).

It may also be a Dell notification error. I have a xps that sometimes fails to recognise the (Dell) power adaptor. Win7 reports it as unknown, and won't recharge the battery.
In this state F14 shows the battery as fully charged regardless. At other times (when the adaptor *is* recognised correctly), F14 reports the battery correctly.

@macemoneta : Thanks !
I have version 2.6.35.12-90.fc14 . So i dint get why this bug is not fixed in mine , because it says that this bug was fixed in 2.6.35.10-74.fc14 .
Also the status of #656738 is "CLOSED ERRATA" . I dint quite get what that meant . Doest it mean that i cant install this patch anymore ?
Also when i tried yum install patch i got the following output :
Package patch-2.6.1-8.fc14.x86_64 already installed and latest version
No package 656738 available.
So is this some other bug ??..
Thanks again!
@sygOO : Thanks !
I do not think its a notification error , because i have never had any issues with adapter recognition . Its just that when i remove the adapter after its charged , it shows battery critically low and then suspends . Best guess is that its a bug !
Thanks anyways !

I dont think this is a Fedora specific issue anymore . The reason being that after I installed Natty (Ubuntu 11.04) as the battery issue was being too inconvenient for normal use , i found out that the same happens in Ubuntu too .
I hope this will help to shed some light .