Right now I'm using a trail tech battery pack while I wait to get paid to buy a wr426 stator so I can have more juice. I believe it's a 3700 mah Nimh battery. With radio controlled helicopters being my other hobby, I've got several lipo batteries laying around. A 3s lipo puts out around 12.6v when fully charged, I could use a much higher capacity lipo pack in my yz426 and have a lot more running time in between charges. Knowing that lipo and Nimh are two totally different technologies, would it be safe to run a lipo and have the reg/rec charge it? It's a different setting on my multi chemistry battery charger I use for my lipos... I'd hate to have a lipo fire under my butt while I'm riding a trail.