True Dual Battery Kit

This is a great kit for adding that 2nd or 3rd battery system in your car, boat, RV or whatever you wish. It utuilizes the simplest and most advanced technology to keep all your batteries charged using the engine’s electrical system but isolating the starting battery so you never get stranded.

The 12V dual battery kit uses the same relay we have installed in our boat and camper to keep the accessory batteries charged but isolating the starter battery system so it stays charged. The great thing about these is that you don’t have to reroute any alternator wires and they are all automatic. Everything you need to do the job right yourself.

  • Suitable for 12V Marine,4WD,Caravan & Solar
  • 140 Amp Voltage Sensitive Relay
  • Priority charging for starting battery
  • Alternator outputs up to 150 amps
  • Fully Automatic, Proven Technology
  • Easy to Install

$129.95 free shipping

In Stock Shipping now

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$129.95 free shipping

“Currently In Stock”

Your Country



  • 1 140 Amp Voltage Sensitive Relay
  • 1 19’ 8” length of battery cable
  • 1 Ground Cable
  • 2 Positive brass marine type battery terminals
  • 1 Negative brass marine type battery terminal
  • Tinned copper lugs & heat shrink
  • Cable Ties
  • Easy to follow instructions

dual battery isolator kit

dual battery isolator kit

The 12v dual battery isolator kit allows for safe charging and separation of starting and auxiliary batteries in all Volt Marine, 4WD, Caravan and Solar applications.When the engine is started, starting and auxiliary batteries are separated allowing only the starting battery to be charged. When the charge voltage reaches 13.3 volts the voltage sensitive relay engages allowing both the starting and auxiliary batteries to be charged.

This is indicated by the light in the top LH corner being illuminated.

When the engine is stopped and the battery voltage falls below 12.8 volts the VSR disengages separating the start and auxiliary batteries, at this point the indicator light will be out and the 12v auxiliary battery kit continues to power any accessories without risk of draining the starting battery.

The VSR also has Dual Sensing which senses the charge of both batteries. If either battery is receiving a charge, e.g. a battery charger is connected to the auxiliary battery; the VSR will engage and charge both batteries.

The 12v dual battery installation kit is easy to install and comes with all components and instructions required to complete the install. There is no need to cut into any factory wiring that may void manufacturer’s warranty.

tag: dual battery kits, dual battery relay kit, dual battery isolator kit, dual battery wiring kit