The Dell Mini 9 has been sitting on the corner of my desk for several months now, unloved and more importantly uncharged. I'm going on vacation soon and I wanted to bring it along for casual coding instead of my work notebook. I fired it up with a very dead battery and the Dell Mini failed to recognize the battery - ugly orange LED blinking at me.
What to do? Forums suggested resetting the bios by unplugging and unplugging the CMOS battery. That didn't work, despite the fifteen minutes I spent unscrewing the 25 or so screws that hold the Dell Mini together.
More searching led to flashing the BIOS to make it recognize the battery. Dell only provides a Windows executable for BIOS upgrades (too bad for you cheap bastard, you bought a Mini with Linux), but the enterprising users at Dell Mini Forums packaged a image with DOS and the BIOS flasher that runs on a USB stick. The package and instructions can be found on the Dell Mini Forums.
The BIOS flasher checks to see if the both the battery and power supply are plugged; if neither one is plugged in, then it exits. Since the battery was unrecognized, the BIOS flasher exited. This is where it the fun begins. You can make the BIOS flasher ignore the power supply and battery checks by running the BIOS flasher with a /forceit option.
The first time I ran the BIOS flasher, it worked correctly. However, the battery was still unrecognized. I'm a great believer in the maxim, "If it jams, force it. If it breaks, well it wasn't working anyways." So yes, I ran the BIOS flasher a second time, and this time the screen went blank and the Dell Mini would not reboot, despite my frantic poking at the on button.
Fortunately, there are many people much smarter than me who are willing to share their smarts. Instructions for recovering a bricked Dell Mini 9 are available at fosk.it
Sometimes no amount of voodoo and vulcan nerve pinches can recover a thrashed computer, so it seems the only solution is to buy a new battery.