How to Connect a Battery Tender

The Battery Tender product line, made by the Deltran Corporation, is an automatic battery maintenance charger. The company has been very successful with their product, garnering respect not only from many customers that swear by the Battery Tender, but also endorsed by prestigious auto manufacturers like BMW. The Battery Tender is automatic and easy to use, but you do need to take the time to make sure you connect it properly.

  • Set up the Battery Tender on a stable, flat surface, close enough to the battery so that the power cords can easily reach the battery to be charged.

  • Make sure that the AC and DC power cords for the Battery Tender are clear of all the moving parts of the vehicle.

  • Determine what type of ground system the vehicle is operating on. A positive ground system will have a positive post for the battery connected directly to the vehicle chassis, while a negative ground system will have the negative post connected to the chassis.

  • Connect the positive clip from the Battery Tender (or the included ring terminal if necessary) to the positive battery post if the vehicle is using a negative ground system. Connect the negative clip or ring terminal to the chassis of the vehicle. Make this chassis connection to the engine block or some other thick metal part of the frame.

  • Connect the Battery Tender opposite to Step 4 if the vehicle has a positive ground system--that is, connect the negative clip to the negative battery post and the positive clip to the vehicle's chassis.