Hi Tom. I have two of the Expert units. Both of mine run on a SINGLE CELL AA 2500ma NiMH battery. 4.8 volts is too much voltage, and unnecessary weight. Now, with that said, you can expect 100ma per minute drain with the glow plug on. I can fly my Skybolt approx. 10 flights before my glow battery dies. That translates into 20-25 minutes of idle, taxi, and throttling back in the air. My glow turns on at the low end 20-25% of throttle.