Has anyone here used R/CR123A or 18650 batteries in their bots? They seem to be a good power/size ratio. Rechargables seem to be fairly reasonably priced.
I've seem the 138650 @ 2200 mAh w/protection PCB and RCR123A around 1000 mAh w/no protection.
At first I was like "Dud,
At first I was like “Dud, what’s wrong with good ol rechargables”?.. But I needed some info to fire at you… and realized… hey? lighter, longer life, 3V… what is going on here?
With this, could I use only 2 batteries (even lighter) instead of 4 (heavy) to get something like the same power?!?
Exactly! Twice (or more)
Exactly! Twice (or more) the power density. I think I will order some RCR123A today. Or I may go buy 2 non-rechargeable to test with and see how they do. I am having a difficult time finding a dual holder for CR123A.
Polymorph one! :)(holder)
Polymorph one! 
(holder)