In many campervan conversions, keeping an eye on battery voltage can be a very handy feature, especially if you are camping without electric hook-up and have an electric fridge, lighting etc.
You can connect the voltmeter to either the main vehicle battery, used for starting the engine and supplying the vehicle’s 12v electric systems. Connecting the voltmeter to a leisure battery will enable you to see the voltage remaining in your battery for auxiliary accessories such as lighting and fridges. Or you can purchase a switchable voltmeter that enables you to see both battery voltages at the flick of a switch, like the one sold by Just Kampers (J11477).
• Before installing the gauge, disconnect the earth terminal from the main battery in your vehicle and from the leisure battery, so that you do not create any short-circuits which may result in damage or fire.
• Choose a location to mount your gauge, allowing enough room at the rear of the gauge.
• Connect the negative/earth wire on the back of the gauge to an earthed part of your vehicle, such as a bare metal part of the chassis.
• Run a fused wire from one of the positive terminals on the voltmeter to your vehicle’s main battery live terminal or a live terminal on your main fuse box.
• Run a fused wire from the other positive terminal on the voltmeter to your leisure battery live terminal, or to a live terminal on an auxiliary fuse box connected to your leisure battery.
• Reconnect the earth connections on your two batteries that you removed earlier.
• When you have selected either switch position, the gauge should now read the correct battery voltage for that battery.
• Sit back and enjoy the luxury of being able to monitor your batteries voltage levels.