These lights really need 12V batteries. V= 12V says how hard the current (I) is being pushed, and if it isn't hard enough almost no current will flow and there will be very little light. You can either get a 12V battery or put say 10 1.2V batteries in series.
Since the power drawn is P=4.8W, and P=IV, I=0.4 amps = 400mA. So to run the lamp for 5 hours you'd need batteries with a capacity 5*400= 2000 mA-h. A quick glance online turns up 12V rechargables with 7Ah (7000mAh) for $18, but they're lead-acids and a bit heavy. You could no doubt find some sort of lithium-based batteries that would be lighter, but pricier.
Mike W.
(published on 01/30/2016)
