Equipment Needed to Install and Connect a Battery Isolator

Dual Battery

People have been charging and using auxiliary batteries in their cars and RVs with different success rates over the past century. Nowadays we expect much more from our recreational vehicles and we expect them to be able to handle run lights, laptops, TV’s, pumps, winches, fridges, charge mobile and camera batteries, even run microwaves. We basically expect to have all the luxuries of our home when we go camping.
Over the past few years, the demand on auxiliary batteries has increased as we all need safe and fast ways to recharge batteries. In order to ensure all of the vehicle’s batteries are charged from the vehicle’s alternator, we use battery isolators.

A battery isolator divides the DC (direct current) into more branches and only allows one current in one direction in all branches. The main benefit of a dual battery isolator is the ability to simultaneously charge multiple batteries from a single power source, in this case an alternator, without having to connect the battery terminals together parallelly.

The Necessary Tools to DIY

Connecting a dual battery isolator is pretty straightforward, but before attempting to do it, make sure you have a few necessary materials and tools. Planning ahead for this process will help ensure your project goes smoothly. You’ll need a few accessories to safely and securely install a battery isolator, red and black cables, terminals, a switch, and potentially some other equipment which we’ll discuss in a moment.

The red and black cables are wires which are insulated with a plastic coating, coloured respectively in red and black. The red wire directs electrical flow between the isolator and the battery, while the black cable grounds the isolator to the RV. A set of each is essential to install the isolator properly.

Terminals are rings that have plastic screws which provide connection points for the cables. They help shuttle the power between the isolator and the battery. If the terminals have corrosion or are worn out, they should be replaced.

The switch, also known as a kill switch, can turn on and off the isolator if needed. They’re available in different sizes and in a variety of styles. Furthermore, items like wire lugs, zip ties and an electrical tape can help you install the isolator more conveniently.

Connecting the Isolator

The most suitable location for the installation is under the vehicle’s main bonnet or in a not-so-crowded area, like a car’s boot. Installation techniques are different for different types of isolators or different brands, so you should make sure you know what you’re working with before beginning. It’s important to follow the exact instructions provided by the manufacturer. Most installation instructions require grounding the isolator or the battery (or both) to the RV. Connect the positive terminals with the red cables on the main battery to the battery isolator, the vehicle’s electrical system and alternator, while the positive terminals on the battery are connected to the isolator and the appliances you need powered.