thanks for the tip! I'll try out two 17670s and an MN11 in my M4. How's runtime?
Well, it pulls 2.5 amps. I'm guessing you'd want to stop when the batteries were at half capacity (800mah), so I'd assume about a 20 minute runtime. You could do slightly better with a pair of 16650 (2000mah as opposed to the AW17670 1600mah).