DISCOVERY 4 Dual Battery Kit  D4-5D is $735.00

The D4-5D kit is made in Australian.

There are no other types of Discovery 4 Dual Battery kits that offer anywhere near the operating and charging advantages that our D4 kits achieve.

Our Discovery 4 kit will allow you to recharge batteries at up to 6X faster than a DC/DC device

NOTE you do not require any form of electrical experience to fit this kit and you only need basic handyman skills and some basic tools to install this kit.

21 D4-5D-M

The D4-5D is a combination of three kits, the Cranking Battery to Auxiliary Battery Plug-N-Play kit + the Power Socket Extension kit + the Heavy Duty Power Cable kit, which provides charging power for house battery(s) located in a caravan or camper trailer.

Because of the unique way the D4-5D operates, you will have a total 110Ah to 120Ah of usable accessories power available, and with any other type of isolator, you will need to fit a 150Ah auxiliary battery in the rear cargo area to achieve the same amount of useable accessories capacity.

So this kit will save you money, weight and space over any other D3 dual battery set up.


The D4-5D kit includes the pre-wired DT90 isolator & In-Line Circuit Breaker,  Battery Bracket and Hold Down Bolts,  Auxiliary Battery Earth Cable, a Power Socket, Fuse Holder, Heavy Duty cabling to the rear, 50 amp Anderson plug and all necessary Hardware to complete the installation. All you need is the Auxiliary Battery.

All cabling has been cut to the correct lengths and all terminals have been pre-assembled including Heat Shrink and Split Tube protection, so there is no need for any special tools when fitting one of these kits.

The kit has extensive installation and operating instruction, which include numerous photos to assist in making the installation easy for DIYers.

You only need some basic Handyman Tools to complete the installation.

This kit takes about 5 hours to fit. You only need to cut one hole, in the rear cargo area, to mount the new Power Socket. Everything is assembled and ready to install and the price includes Australia Wide Postage.


Again, with the unique way the DT90 operates you can connect solar panels ( via a solar regulator ) or a battery charger to either battery in an DT90 dual battery set up and all batteries will recharged.

REVERSE CHARGING. If you have an Anderson plug mounted at the back of your vehicle, you can make your solar or battery charger connection through the Anderson plug and again, all batteries in an DT90 dual battery set up will be charged. If the SC80-BM has turned off, once the Auxiliary battery is nearly fully charged, the  DT90 will turn on and allow the Cranking battery to be charged.

All our isolators are supplied with a 5 year Parts and Labour warranty and a Lifetime Repair Guarantee.

Please note, this kit is NOT suitable for most models of the Discovery 4 ( & late model RRS ) outside Australia, where there can be either a Fuel Heater or Air Intake box fitted in the space just in front of the Cranking Battery Compartment.