I want to buy the Magic Pie 3, but the battery is really expensive. I saw the MiroMax video where the guy explained that there were different batteries you could use. The video showed one that looked like a water bottle. I can't find these on any site and when I find sites that sell batteries it's always that big one you fit on the rack that costs 400 something dollars. That's a bit out of my price range to spend almost 1000 dollars for everything. I just wanted to know if anyone knew of a cheaper battery that worked as well or one that gets less performance but still works properly.