I've got a 10w MR-11 light right now. Don't have a regular commute or anything, so I've been using for afternoon rides where I get caught up after sunset. Probably about 1-1.5 hours a day. I have put a female DC socket at the end of a 12" lead on the battery and a matching plug on the light. I put the same plug on my 12v smart/trickle motorcycle-battery charger. So I just unplug the light from the battery and plug in the motorcycle-charter. This way I can also use the AC/DC brick 12v transformers that's common as well. Recharge about once a week overnight, about 8-hours on the smart-charger.