Looking at the link, I would say those batteries are not high enough in capacity to be worth much. I now run my mini-me off of 4 6v 4000mah nimh batteries, and I get about 4-6 hours run time off of each. I have two wired in parallel so that I can run two batteries, switch batteries mid set, etc without causing a power interruption. I would look for higher amh batteries on the same site, or else look into sla batteries. Why not power it via the firewire?
Daryan