Anyone seen these?:
http://www.amazon.com/Anker-10000mAh-External-GT-P1000-GT-P1000N/product-reviews/B005NGLTZQ
Same price as my old Walmart batteries and a USB as well, plus 10000 miliamps.
Hmm.....
Hey Z-man,
Don't really have a good recommendation for a battery, but for some insight on this one:
I have a smaller version of an Anker battery for use with my Sound Devices USBPre2, running at 5v. It is a nice battery and works well. But my battery, and I'm sure this one, spec's out it's mA-hr rating at the level of the 3.7v internal li-ion batteries that it's built on. This is misleading, though seem to be common among battery makers.
You'd want to run your V2 at 9v (ideally 6v, but 5v will be too low), so the Anker battery needs to step up the 3.7v voltage of its internal li-ion batteries to 9v with a DC-DC converter.
As a rough estimate for a mA-hr rating at 9v, you have: 3.7v / 9v * 10,000mAh * ~85% (since the DC-DC converter will not be 100% efficient).
Thus, at 9v operation, this battery is probably more like 3500 mAh of capacity, or enough for 6-7 hours of usage for the V2. Not bad, but not as good as the reported 10,000mAh makes it seem.
EDIT: Looks like kirk and I were posting at the same time, but my bet for mAr rating is what I have stated above. I've done testing with mine, and based on current draw and time of operation, it really looks like my 5600mAh Anker battery is built on 2x 2800mAh li-ion cells (18650 cells I'd guess from the size and shape of my battery).