ORIGINAL: rblubaugh
You can probably use a 5AH battery. There's a couple of them ending in less than 15 minutes as of this writing with free shipping. 5000mAh should last about 2 hours or more depending on throttle and accessories (lights, hoists, etc) If you're planning on a lot of accessories you could use 2 paralleled.
Watch out for date coding!
Ok, if 5Ah is good, would 7AH be better or even 10AH. As it sits and in order to keep the weight of the battey at or near the CG, I'll only be able to run one battery.