The diode is in there for reverse polatity protection. There is no devious attempt to get you to buy something from them. It's a protection in the circuit.. protects their warranty program. If you put the battery in wrong, and there wasn't this diode in there, well, they would be replacing a lot of transmitters.

Irish.. jeez.. you got enough capacity there? ha.. My friend, long time pattern type (over 35 years in the hobby) scoffs at my 1200 mah RX batts.. says 900 is plenty. Like you, I just like that comfort zone of having lots of available charge left after I fly. I don't like looking down at my Voltwatch after two flights and seeing it flicker in the yellow zone (caution zone on the Voltwatch). I have 1650's in my TX's, and that seems to work out fine... again, I like that extra capacity just for the comfort zone...

CGr