This the size off the engine you have . WHAT A ENGINE (WOW) This engine needs help to turn starter motor,Alternator.THERE ARE Fuses,relays, switches,lights, ALL to get power to that big engine.There are people out there who can explain this better and with more technical expertise but basically it needs a lot of power to start engine.At the moment car companies are trying to develop a 36 volt battery to cope with todays cars because 12 volt batteries can't cope with excess electrical equipment.hope this helps