T430s won't boot with battery in

[jhathi]

Hello!

Got a weird issue with a refurb T430s I just picked up. It won't boot with the battery in. If you take the battery out, then start the computer with just the charger, it comes up fine. You can then put the battery back in and it will charge fine and the computer continues to work. You can even get the computer to sleep and wake from battery fine.

I've reset the BIOS to defaults and upgraded it to the latest version to no avail. Anyone got any ideas as to what is going on?

TIA!