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dual battery isolator

Discussion in 'Truck & Equipment Repair' started by dfrommi, Jan 6, 2010.

  1. dfrommi

    dfrommi Junior Member
    Messages: 2

    hello new to the forum. we are running into issues with plows at my work.
    i would like to add a dual battery setup with a battery isolator.

    i need a simple correct way of setting up a aux battery only for the plow lights and a salter+what ever else down the road. just bought a 120 amp 4 wire alt for a chevy 350 vortec
    also have a SurePower 120 Amp Battery Isolator [​IMG]

    if i hook up the system by the instructions on http://www.surepower.com/pdf/180012n.pdf
    (special instructions for group 2) will the aux battery be over charged? if not what is keeping it from over charging?
  2. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    The simplest and most reliable way to have two batteries is to simply wire them in parallel with 2 gauge welding wire. That will give your plow the most available power. If you want the batteries isolated, use a relay/contactor such as Trombetta. You need continuous duty, 200 amp capacity or better.

    The isolator you pictured will work, and will not overcharge your battery, but they use quite a bit of power, and usually create a voltage drop. Not recommended for a plow truck.
  3. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Might try using the search function on the blue line above.
    Search: Duel batteries, charging, etc. There is hours of reading on it. We beat it to death here every month and I post this every 2 days at least. It's quicker then waiting for people to answer your question.