How to Connect a Battery Tender to Dual Batteries

There are so many uses for batteries around the home that it is often hard to keep them all charged. Many lawn, garden and recreational items such as lawnmowers, tractors and boats have multiple batteries. There are devices that can be purchased for charging a series of batteries but they are costly. Charging duel batteries can be accomplished with just a few items found in most home workshops and one good battery tender. The battery tender is designed to charge the battery and automatically switch to the maintenance cycle to maintain the charge.

Things You'll Need

  • Battery tender
  • 2-pieces of 16-gauge insulated wire.
  • 2-set of alligator clips
  • Pliers
  • Wire stripper
  • Electrical tape
  • 2 -12V batteries
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Instructions

    • 1

      Cut two pieces of 16-gauge insulated wire to the length according to how far the batteries will be located from each other.

    • 2

      Strip ¾-inch of insulation from both ends of each piece of wire.

    • 3

      Use the pliers to clamp alligator clips to each end of the wires. Each piece of wire should have a red clip at one end and a black clip at the other. Stretch out the wires side by side so each end of the double strand has one black and one red clip. Tape the two wires together with pieces of black tape every 6-8 inches. This will serve as a wiring harness between the two batteries.

    • 4

      Connect the battery tender to the first battery. The red clip attaches to positive terminal and the black clip attaches to the negative.

    • 5

      Attach the red and the black alligator clips from the wiring harness to their corresponding terminals on the battery, next to those from the battery tender.

    • 6

      Attach the clips from the other end of the wiring harness to the second battery. This will allow the battery tender to charge and then maintain both batteries.