unit i bought(AT04147E-7500W) does not come with battery. product manual does not list battery type or part #? called tech support, very helpful with other questions about unit, but stated since unit is a newer model even they didn't have the answer(paperwork) from supplier yet. does anyone know what type(#),or part #to buy. seems like it would be a standard size motorcycle type, but what #? if anyone has same unit that came with battery, what# ison it? thanks for any help you can give.