RE: Battery install ?
It seems to me that using lithium on ignition is a waste anyway. I use a 5 cell AAA size Nimh pack, it weighs 2 oz. No regulator needed, will fly my DA-50 well over an hour without recharge, and can be recharged in about 5-10 minutes.
Lithiums are great on a receiver, but on ignition I think they add unnecessary complexity.
TF