computer external power pack for P+ series!!!

[NNN637061390402674218]

Hi, I am using technical camera. In the pass battery problem is not an issue for me.
However after Mac change to Thunderbolt, I facing problem with always run out of battery.
so my question is:
1. What is the maximum V of power that P21+ and P45+ can accept?
2. Recently I got a Energizer XP18000A external power pack. Can I use 16/20V power for my P+ back?

Since my camera is not portable type, so battery size is not a matter for me.

[Ulf]

Hi
1. Typically firewire is either 12 or 24v
It does allow for higher fluctuation then this but this is a rule of thumb.
2. This does not have a firewire port which can provide power...