No. The USB port on the pocket is for firmware updates only. The camera needs 12v to run, USB is only 5v and also the USB port is in a very awkward position to use
Thanks for replies, that's great. Gonna see can I get myself a Juicebox Lee, I have a Astro Pro 20000ma which covers me for a full day's Wedding, but I'd like a back up so that may be the one. Thanks again.