A van with solar power is awesome. It means you can live completely off the grid with lights, a fridge, phones and computers while no need to worrying about electric bills or power outages.
However, sometimes solar power is not enough, especially if your budget doesn’t allow you to throw down for a huge multi-panel system. Cloudy weather, wildfire smoke, and camping in shady forests limits the amount of sunlight getting to your panels.
It is possible for a larger four-panel solar system to run into problems with battery drain after 4-5 days in poor sunlight conditions. That is why we highly recommend installing a dual battery isolator in your DIY van build. A dual battery isolator is a great way to supplement your solar panels and make sure your batteries stay topped off no matter the weather. And if you’re on a tight budget, you can even skip the solar and still have basic electricity with nothing but a good isolator and a deep cycle battery.
Every vehicle has an alternator, which is a device that converts the mechanical energy from your van’s engine into electricity and uses that electricity to charge your starting battery. A dual battery isolator is a device that allows you to charge a second (auxiliary) battery from your van’s alternator.
You can easily use your alternator to charge your auxiliary battery simply by connecting the positive terminals of both batteries. However, connecting your batteries this way means that when the engine’s off, your electrical loads will also drain the starting battery – not good if you want to start your van in the morning!
That is where a dual battery isolator comes in handy. A dual battery isolator isolates your batteries so that your alternator will only charge your main battery first when the engine is running, and only charge you second battery in case the main battery is already full. In this case, your electrical loads won’t drain your starting battery.
Dual battery isolators are essential for vanlife. Life on the road means a fair amount of driving, and having the ability to charge your batteries from your engine is a great way to increase your power efficiency and make sure you have electricity when you need it.