The Battery Tender is a trickle battery charger that has gained a reputation among many auto, boat, and motorcycle owners as the best on the market. Deltran, the maker of the Battery Tender series of products, is well thought of among auto and motorcycle manufacturers also. They are the official factory authorised manufacturer of both Harley-Davidson and BMW battery chargers. Deltran recommends a specific way of using the Battery Tender.
Set up the AC and DC power cords for the Battery Tender so that they will not get caught in any moving parts of the vehicle.
Verify whether the vehicle has a positive or negative ground system. Positive ground systems have the positive post for the battery connected to the vehicle chassis. A negative ground system has the negative post connected to the vehicle chassis.
Connect either the positive clip from the Battery Tender, or the ring terminal to the positive battery post on negative ground systems. Next, connect the negative clip, or the ring terminal to the vehicle's chassis. The chassis connection should be made to the engine block or another thick metal part of the frame, not lighter metal items.
Connect the negative clip, or the ring terminal to the negative battery post on positive ground systems. Connect the positive clip, or ring terminal to the vehicle's chassis.
Plug in the AC power plug to an electrical socket. Set the charge mode to bulk mode if the battery is 0% to 75%, or 80% charged. Set the charge mode to absorption mode if the battery is 75% to 100%. Set the charge mode to the storage/float maintenance mode if the battery is fully charged.
Monitor the lights on the Battery Tender. A steady red light indicates that the Battery Tender is connected properly and charging is taking place. A flashing green light indicates that the battery is over 80% charged, while a steady green light will let you know that your battery is completely charged.