Do I really need… Part 13 – Dual Battery System
A dual battery system is one of the things that’s everywhere these days – and with good reason. A quality dual battery system will let you live off-grid for days, or weeks, without needing any outside power. If you’re running a fridge, camp lights or an inverter, a dual battery system will let you power everything without worrying if your vehicle will start in the morning!
The standard way to set up a dual battery system is to install the second battery in the engine bay or tray with a cut-off solenoid connecting it the the main cranking battery. The cut-off solenoid allows the battery to be connected directly to the cranking battery when the alternator is charging the system, but disconnects it when there’s no charge so that any power use doesn’t get drained form your main cranking battery.
There’s a few more options these days. With the advent of good-quality DC-DC chargers and lithium batteries, you can spend a small (or large)fortune on your 12V systems. For most vehicles and systems a voltage sensitive cut off solenoid will be all that you need. If you are doing some serious touring or your vehicle has a smart alternator (one that varies the output voltage) then I’d suggest investing in a good DC-DC charger as this will charge your auxiliary battery a lot better. Most good DC-DC chargers also let you hook up a solar panel for even more charging power.
Another option that’s gaining a lot of traction these days is to not have a second battery installed in the vehicle, but to have a portable “power station” that you can plug into the vehicles 12V wiring and use that for powering everything as well. These power units normally hold a battery, charger and have outlet ports of varying types for connection. These are great because they allow you to remove the battery from your vehicle and use it anywhere else. The biggest downside to these is that you can’t really hard-wire anything into it, so things can get a bit more messy.