Tekkeons are kind of expensive here in EU...
The New Trent IMP120D is 12000 mAh. Yesterday, I was testing it with my USBpre2. 2ch, 48v on (U87 and a TLM49), 1 o´clock on pres. The New Trent was powering the USBpre2 for 11´5 hours and it still had enough juice for about 3-4 hours.
I am getting a Tascam DR100 mkII... the point is that it can be USB powered too, so the IMP120D is perfect for this couple
Cheers,