[Firediver]

You could use the same type canister I am using for my 50W Halogen dive lite. I am using 10000ma NiMH D cell batteries 10 of them to be exact. I found with the NiMH batteries they don't see to have memory and can take over charging without issue. As for overdriving I haven't done it. Really don't see the need to either. I get great burn time from my light now as is and it bright enough for now.. I have some pictures posted of my light and canister under the DIY canister light thread.. in more then one of the DIY light threads actually...... I purchased my batteries on E-bay as that is where I found the best deal.