“What is a dual-battery system, and is it worth it?”
Like most camping gear, a dual-battery system is not a necessity. However, it can make life a whole lot easier if you’re camping in remote locations.
As the name implies, a dual-battery system is nothing more than a second (or auxiliary) battery in your vehicle.
The auxiliary battery recharges while you drive (thanks to the alternator), and is typically connected to your vehicle’s main / starter battery.
This second battery allows you to power your camping fridge and 12V lights without the risk of draining your vehicle’s starter battery. Thus, leaving you stranded.
However, in order to safely do this, you need some sort of isolating switch between the two batteries so that you don’t accidentally deplete the auxiliary battery, and your starter battery, at the same time.
In the “old days”, people simply used a heavy-duty switch which they’d manually turn to connect the two batteries (when they were driving), and then turn the switch back again (to isolate the two batteries) once they’d arrived at camp.
Admittedly, this setup still works well in most vehicles, the only problem is: Remembering to manually operate the switch each time.
ENTER: The automatic dual-battery isolator
Initially, the first commercially available dual-battery systems consisted of a solenoid switch that would engage when the engine was running, and then automatically disconnect when the engine was switched off.
To this day, solenoid-based dual-battery systems are still one of the most cost effective, reliable, and proven ways to install a dual-battery system in most vehicles.
However, as more modern vehicles adopt variable voltage (intelligent) alternators, there are circumstances (in certain vehicles) where a solenoid-based system is not as effective as a DC-DC dual-battery system (a newer technology that can alter the voltage entering your auxiliary battery).
So, is a dual-battery system worth it? Well, only you can answer that question, but the two blogs below may help you decide.