I have a Bosch battery with JAP (small) terminals ah45 and crank of 330. It is really sluggish when turning the ingition and looses charge after a few days of standing. I want to get a more powerful battery 60ah and 500 plus crank. Trouble is I cant find one that fits. As anyone changed their battery for a larger one and changed the terminal lead connections to fit the new battery with standard terminal?