My Dell Inspiron 6000 wont run on it's battery. The battery says it's charged, and 100%. The battery charge indicator on the battery is 100%. I've checked the power cord and it will run the laptop without the battery connected. However when the A/C power is disconnected and the laptop jumps to battery power, it immediately dies. I've checked and updated the BIOS, and everything checks out...any suggestions would be helpful.