I will not be driving my Mav for about 9 months. What do i need to do to ensure it will start when i get back? Are there 2 batteries or just 1? Fuel additive? When reconnecting battery, what won't work?
I would put it on a battery tender.. drive till gas light comes on and tank is almost empty, put some fuel stabilizer in it. That way when you're ready to use it again drive it to the gas station and do a fresh fill up.
maybe also put it in a hepa filtered positive pressure clean room, on race jacks so you unload the suspension and not flat spot the tires.
Fuel additive yes. The regular 12v battery under the seat could use a battery tender (hooked up to the jumpstart points under the hood). I'd drive it some before parking, so the High Voltage Battery has some charge in it.
One last decent downhill braking opportunity to get the HVB charge as high as possible.
Ditto's to above comments.
Manual comments on long term storage too - don't forget what's recommended by Ford themselves.