D3-TB2 Discovery 3 / 4 Triple Battery Kit   

Price $765.00


There are no other types of Discovery 3 or Discovery 4 Dual Battery kits that offer anywhere near the operating and charging advantages that our D3 & D4 kits achieve.

Our Discovery 3 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.


The D3-TB2 is similar to he D3-TB1 is a HIGH CURRENT Triple Battery kit, but is supplied with the Power Socket Extension kit which includes the ABG-25 isolator, our Low Voltage Cut-Out Unit, for protecting the Auxiliary battery from being accidentally over discharged and is specifically produced for a Discovery 3 and early model Range Rover Sports. This kit can be installed in a Discovery 4 and late model RRS, with some rearranging of the components in the D4’s Auxiliary Battery compartment.

This kit has been developed to bring together the benefits of a number of advanced components, to be used in a Discovery 3 or Discovery 4, fitted with an electric winch. These kits utilises the USI-160 Isolator’s ability to join batteries together for winching operations,  and  exploits the high current capacity alternators in a Discovery 3, Discovery 4 and Range Rover Sport, to rapidly replace the used energy of the two fast charging Optima Yellow Top Batteries while resting between winching operations.

Another benefit is because of the unique way the USI-160  operates ( in SHARED Mode ), you will have a total 135Ah of usable accessories power available, whereas with any other type of isolator, you would need to fit a 160Ah auxiliary battery in the rear cargo area to achieve the same amount of useable accessories capacity.

CLICK HERE to see full details on how SHARED mode works and other USI-160 features, see the USI-160 page.

So this kit will save you money, weight and space, over any other Discovery 3, Discovery 4 and Range Rover Sport dual battery set up, and there is no other dual battery set up that can offer all these benefits.

The kit includes the USI-160 Heavy Duty Isolator, an In-Cab Module, our D4 Stainless Steel Battery Tray, Battery Bracket and Hold Down “J” Bolts ( for auxiliary battery 1 ), Battery Bracket and Hold Down Bolts ( for auxiliary battery 2 ), three Heavy Duty Positive Cables, two Heavy Duty Auxiliary Battery Earth Cables, 2 sets of Battery Terminal Clamps, Circuit Breaker and Power Cable to the rear cargo area, the ABG-25 Isolator, a Power Socket and all necessary Hardware to complete the installation. All you need are the two Optima D34 Yellow Top Auxiliary Batteries.

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.

All the cabling has been cut to the correct length and all terminals fitted and protected with heat shrink and the positive cabling is covered with split tube.

CLICK HERE to see full details of how the ABG-25 operates, on the ABG-25 page.



This kit takes about 4 hour to fit. You only need to cut one hole, in the rear cargo area, to mount the new Power Socket. Everything is pre-assembled and ready to install and the price includes Australia Wide Postage.


Again, with the unique way the USI-160 operates in the SHARED Mode, you can connect solar panels ( via a solar regulator ) or a battery charger to either battery in a USI-160 dual battery set up and all batteries will recharged.

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 a USI-160 dual battery set up will be charged.

But if you have a specific need to only charge your Auxiliary Battery, then by selecting IGNITION Mode and connecting the solar panels or battery charger to the Auxiliary Battery, you will be able to charge it, while the Cranking battery remains isolated.

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 fitted in the space just in front of the Craning Battery Compartment. The range of Discovery 3 kits will fit a D4, with some rearranging of the components in the D4’s Auxiliary Battery compartment.


Review D3-TB2 Discovery 3 / 4 Triple Battery Kit   .

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