X10 Low Temperature Powerpack Project.

I travel a lot in very cold environments (-5° to -30°c) and I have until now kept my cameras running by the usual rigmarole of swapping batteries every few minutes from my warm pockets to the camera which is kept outside my clothing to prevent condensation. Inconvenient to say the least.

(This shot taken with my now deceased Canon G10)

Many years ago I had a handy gadget for my A series Canon cameras that linked a small battery holder carried inside the clothing to the camera outside via a cable.

My intention is to make something similar for an x10 using the CP-50 DC coupler unit.

http://www.fujifilm.eu/uk/products/digital-cameras/accessories/power-accessories/model/cp-50-coupler/overview/?tx_fujifilmproducts_pi1[accessory]=1&tx_fujifilmproducts_pi1[prev]=4269&cHash=490efa05a939b8a27c2a858daa7aceae

This is where I need a little bit of technical advice. It's a long time since I learned some basic physics at school.

As far as I can see, the AC-5VX AC power adapter that this is supposed to couple with produces an output of 5 Volts at 1.5 Amps. (I hope I'm not missing anything obvious.)

http://www.fujifilm.eu/uk/products/digital-cameras/accessories/power-accessories/model/ac-5vx-mains-adaptor/overview/?tx_fujifilmproducts_pi1[accessory]=1&tx_fujifilmproducts_pi1[prev]=4269&cHash=57d1e32cbd3823dbc25c3bd52ce70c2b

So, is there any reason that this power could not be provided by a rechargeable USB style power pack along the lines of this one?

http://www.dealextreme.com/p/rechargeable-dual-usb-10000mah-emergency-battery-pack-w-adapter-for-cell-phone-more-110237

If that one is not suitable, does anyone know something else that would do the job?

--
Wayland.