I agree with Tom, the vibration that gassers can generate will kill switches and batteries over time. The use of two packs and switches is a really prudent idea in these planes. The big problem is that when your using 5 cell packs the weight can become an issue pretty quickly. I had 2 1400 man Nicads in my edge when I first se her up and they were about 6 ounces each, add in a pair of switches that were about an ounce each and that is 14 oz. or nearly a pound. I decided to go to Lithium Ions with a failsafe switch and that shaved some weight off of the overall set-up. I think it was worth it in my case since I changed a few other items to save weight as well. In the end I took over a pound off of my edge and the effort was well worth it as the plane flies so much better when I get it slowed down.