I decided I did not want to go to a123 batterys as this would mean a new charger and different battery chemistrys to deal with. I like nimhs, cheap and I can load test to see what is left in them, also have a few lying about. If every oz counted then for sure a single a123 sounds good but I still would prefer it to be isolated from the ignition vai some sort of filter.

I use two 6 volt 2100mah nimhs into two switches then into two seperate rx channels. This gives me full redundancy and doubles the availible amperage of a single 6v nimh.

I then use the tech aero ultra bec to supply a optically isolated and regulated 5 volts to my ignition, this alsoacts as a kill switch.

Prob would only recommend this for up to 30cc gassers.

Loads of differentways of doing thingsand geting the same results.