The driver for my 1.35 watt 532 takes 5 VDC in. I have a 5 VDC 20 amp PS to run it. It's a bit of over kill as it doesn't need that much power. But, if I wanted to run it outside somewhere, all I'd need to do is add several 26650 batteries in parallel. Then again, 4.2 volts might not be high enough, but it wouldn't be difficult to run off batteries.
A beefy DC-DC converter and a 12V SLA would work well too. Hell, just wire up some 7805s in parallel and use those.