Latitude XT - Weird Boot Issue

So we have a Latitude XT tablet. I'll do my best to describe the issue.

This seems to be the norm when we leave the laptop unplugged or the battery isn't charged or something. When we boot the laptop for the first time in a while an error message comes up after the POST. It does some DELL diagnostics where it checks the hard drive, ram, etc... I can cancel it out and it boots into windows. Next time I boot the machine or restart, it goes like normal (POST to Windows boot).

After the second time, I can run off the battery and it doesn't do the diagnostics. It only appears to do it after a while. Is this a battery issue or the small internal battery in the laptop? Is it something else?

 

What is the error message?
Sounds like it could be related to your BIOS battery.

Generally that gives you a "press F1 to load defaults" type message though...