Ok I know this is slow but I can't seem to find any info on this. I currently have a RF-6 2 channel receiver. I see that on the receiver input 1 and 2 are being used in which I assume one for the throttle? as well the servo?. What got my attention though is that there is a third input labeled B on the receiver. Can anyone tell me what this is for?

Battery. If you are running it in an electic vehicle you don't need a battery to power the rx, it gets its power from the esc. You use a battery when running nitro.

Thanks. So basically it's used as a battery input to power the receiver in nitro? B for battery makes sense. Thanks again.