I agree with ^^^^ Phi this is something i have also had challenges with as i have had ten people give me ten answers currently i run I normal starter batt with around 20ah and 1200cca connected to duel OPT YT and they work ok but i was tempted to buy a single big ass battery that was 200ah and 1500cca but it was around the 63kg mark and only just fit into the wheel weel then somepeople say you can get smaller AGM batyts or you can get gel batts whats the difference between them and say deepcycle optimas should have read the rest of the posts