DUAL BATTERIES & ACCESSORIES
A dual battery system is a vehicle battery system that uses a secondary battery in addition to a vehicle’s starter battery. This secondary battery is used as a power source for auxiliary gear and accessories.
In a dual battery system, both batteries function as two isolated systems. While your vehicle’s engine is running, your starter battery works with your alternator to power your vehicle and its electronics.
While your vehicle is turned off, your secondary battery powers all gear and accessories attached to your vehicle; meaning that you can run your portable fridge, lights, and inverters without having to keep your engine running.
This is achieved thanks to the function of an isolator that disconnects your starter battery from your secondary battery, meaning that you only draw power from one battery at a time.
The Pros and Cons of Installing a Dual Battery System
If you’re unsure if a dual battery system is right for you, consider these pros and cons.
Pros
Allows your rig to power a fridge, radio, lights, inverters, and whatever else you need while you have the ignition off
No need for concern in draining your starter battery
Increases power available if you need to use your winch
Able to charge your secondary battery with solar panels
Peace of mind in case of primary battery failure
Cons
Added weight to your rig due to an extra battery box
The potential cost might be too high if you’re on a tight budget
Types of auxiliary batteries
Lead Deep Cycle
Suitable under the bonnet, or in an open tray or tub. Cheap, but are known to suffer from a reduced lifespan if not fully discharged and recharged each use.
AGM
The popular choice among any rig, AGM batteries are suitable anywhere as they do not let out any hazardous gases while charging. This type of battery is better suited to partial use and recharge, rather than fully discharging and recharging in a use cycle.
Lithium
Boasting reduced weight and increased capacity, lithium batteries are the most durable battery when used in a partial use cycle. However, due to heat restrictions, these cannot be fitted under the bonnet of a vehicle.
