TabletKiosk have just launched the MP3400 power bank that can be used with many portable devices including UMPCs.
For $159 you get a 56W/hr battery (more than twice the capacity of the standard battery on the v7110 and i7200 series UMPCs) along with a number of tips for using the battery with different devices. There’s also a mains adaptor. The battery is adjustable for voltages between 9 and 19V and from what I can see, you can charge the device through a 12V supply.
Considering a standard 24W/hr battery for the i7210 costs $90, this represents pretty good value for money. Just remember to adjust your power settings because when you plug this in, the UMPC will think it’s connected to a mains supply and switch to a less efficient power setting.
More info here.
