I ordered my light years and years ago, but Dinotte themselves did actually include a "C" size battery holder that held 4 batteries that hooked up to the light for longer runtime. After I got it though, I realized that the C size batteries that are cheap (from Duracell, Energizer, etc) actually had the same rating as the AA version (apparently they just wrap more material around a AA core). They cost $40 for 4, plus the extra cost for a "C" size charger...at that cost, it was about the same to just buy the lith-ion version of the light. The lith-ion battery is way easier to charge as well. I keep my bike by a power outlet, to charge the battery I just disconnect the wire from the light and plug it into the charger - don't even take the pack off the bike.