How to Use Large Inverters With a Battery Isolator

Large power inverters are used to convert DC (direct current) to AC (alternating current). The most common inverters convert 12 volts DC to 120 volts AC. These inverters consume a large amount of current and can quickly deplete a single car battery. This is why isolators are necessary: isolators allow two batteries to be connected to the charging system, but only one of the two batteries can be depleted at one time. This allows one battery to stay fully charged.

• 1

  Disconnect the positive red battery cable on the vehicle's existing battery. Mount the battery isolator as close to the existing battery as possible and secure it to the engine bay using screws. Connect the positive red battery cable that you just removed to the center charging terminal on the battery isolator.

• 2

  Connect one end of the first new red battery cable to the starting battery terminal on the isolator.

• 3

  Connect the opposite end of the first new red battery cable to the positive post of the existing starting battery.

• 4

  Connect one end of the second new battery cable to the second battery terminal of the isolator.

• 5

  Connect the other end of the second battery cable to the positive terminal of the second battery.

• 6

  Connect the negative post of the second battery to the vehicle frame.

• 7

  Connect the positive red power wire for the inverter to the positive terminal of the second battery -- not the starting battery.

• 8

  Connect the black negative wire from the inverter to a metal part of the vehicle frame or the negative post of the second battery.