You could try and make a pack(s) using A123 2300mAh cells and if that's not enough voltage, go with as many 1100mAh cells as you can. The cells in Bosch's 36 volts power tool packs seems to have a 60A fuse and I'm wondering if it can actually handle 60A discharge. I might have to try it out and see how well they do. Here you can see the other pictures:
http://www.rc-monster.com/forum/show...8&postcount=30