In my other thread about dinotte lights, someone told me what voltage they use. I recall they are easy to drive. I think they must use liion cells in their battery packs.

Just searched, I had previously figured out they are 7.4v, which is two Li ion cells in series. I imagine packs like that are pretty easy to find.

Now I just have to figure out what the connector is. I'm pretty good at that, I just haven't had the energy.