ORIGINAL: NJAIRSTRIKE
how long do receiver batteries last?
They last until you use up the energy stored in them. This will vary based on the size of plane, flying style, condition of the batteries, how easily the control linkages move, etc. Bottom line, it's not possible for anyone here to answer your question. In case you haven't already heard, you should get a battery tester so you can check the receiver voltage at the field.
Should you have more than one when you go to the field?
I never bring more than one per plane. I find it way too troublesome to remove the wing, pull the battery, wrap a new one in foam and put it back in the plane.
Is it better to have two Flat 4.8V 600mAh or more more MAH battery?
Battteries come in many different shapes and capacities. I have 300 MAH, 600 MAH, 650 MAH, 1350 MAH, and 1650 MAH packs. Each size is appropriate for its intended size. I've never used two receiver packs in one plane. If you need more capacity, get a pack with a higher capacity.
Should you get a charger that can be charged using your car battery instead of going back home?
I've managed to get by for years without needing a field charger. I know some people who show up at the field and the first thing they are doing is hooking up their charger. Personally, I think this shows a lack of planning, it's pretty easy to plug in a plane the night before.
One more thing, Red's site has lots of useful information, perhaps you could spend a bit more time there.
