Sat in my shed I had 2 batteries and a charger from an old Dewalt drill that no longer worked reliably, luckily there batteries whilst not great for drilling did seem to hold some kind of charge and also happened to be 12 volts which was the same as the iQue, I also had the US power supply supplied with the iQue
Battery, 12V 1.25Ah

Fast charger

I cut the socket off of the US power supply and did some dodgy test wiring

Plugged in to the iQue and watched the system kick in to life

The fan spun in to life at warp speed and switched off, my heart sunk, 10 seconds past by and it started spinning again at a slower speed and just kept on spinning, I guess my shed was no where near the 225 set point.
I left it running like this and it managed 8 hours with the fan running 100% of the time, after the 8 hours the fan started to slow down but carried on running for another 8 hours, pretty impressive! I would predict under normal operating conditions where the fan is running constantly I could get 16 to 24 hours without worrying
I haven't gotten around to finishing the wiring and making it a little more professional looking but I now have a battery powered iQue that I will use when I get back to the UK next week, I can't wait.