Abu like you I can be electronically challenged.i ventured into gas airplanes.i have a wild a by hair edge 540. I purchased a DLE 30 and was told what servos to use.the rudder was probably over kill .then I was oh you don't need dual batteries for a 30 cc plane.so I bought a salsa be eliminator and that was a good investmeni didnt do anything for a year.then I questioned why not use a redundant battery installation.i did upgrade earlier to an 8 check futaba fg.fabulos radio.i have enough ports.so I bought 2 life batteries from wrong way rc here in florida.the additional weight in my opinion is nominal.many of the big gassers are over powered and trust me nothing wrong with that.i did buy a miracle dual switch.i learned years earlier that inadequate switches can kill your plane as easy as a bad battery.the wiring of the switch is heavy gage twisted wire.if you use a rx with less ports of course you can piggy back.y harness the spare battery into your throttle port.no biggie.u will get a better peace of mind.is it fool proof .hardly but nearly 80 percent of failures come bad batteries and switches and connections.if a critical servo locks up you can pretty much figure you will crash. And the second battery doesn't need to be the same capacity as your primary are battery.but a smaller battery same chemistry will get you down safely.
Hope that helps.
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