I would connect a trickle charger like this one http://www.jcwhitney.com/battery-tender-junior-battery-charger/p2009942.jcwx?filterid=j1 and use fuel stabilizer in the gas tank. For added security, you can remove the battery and connect it to the charger in a separate location from the vehicle. Just make sure the location where the battery and charger are is well ventilated, and disconnect the negative terminal first.