Some chargers will not show any current going thru them unless they are connected to a battery. 24 volt chargers are really 2 chargers in one and do not share a common ground. Your charger may have a fuse inside that is blown. If you need another you can buy a minn-kota on board 2 battery or 24 volt at wallyworld for around $100.00, just plug it up and leave it on untill you use the boat again.