Did you know that your car might actually have two batteries? First seen in some higher end European cars in the early 2000's, secondary auxiliary batteries are becoming more and more common across all car brands. Learn more about what auxiliary batteries do and what you can do if yours fails.
Do new cars have auxiliary batteries?
The more electrical equipment installed in new vehicles, the more strain on the starting battery. Flash forward a few years and auxiliary batteries are still fairly rare but you will now see secondary auxiliary batteries in many cars ranging from Mercedes Benz, BMW, Chrysler, Jeep and more. How Do I Know if My Car Has an Auxiliary Battery?
What is an auxiliary battery?
Auxiliary batteries vary in size and specification dependent on the demands placed on it by the vehicle electrical system and can be used as a safety back-up to support the main battery when required or to provide voltage for specific vehicle systems all of the time.
What are the different types of auxiliary batteries?
Types like lead acid and lithium serve varying purposes based on their chemistry. Dual battery systems act as reliable backup power, vital for off-grid travel. Maintain your auxiliary battery by checking electrolyte levels regularly. Deep cycle batteries, designed for sustained power, are ideal for marine use.
Some utility vans will have auxiliary batteries to power active anti-theft systems. All hybrid and electric vehicles (EVs) have a high-voltage battery to provide drive power to the vehicle, but they also have a 12 volt battery to power everything else.
What type of auxiliary battery does a diesel have?
The location and type of the auxiliary battery depends on the vehicle's specifications. Most light vehicle diesels will have two main batteries wired in parallel. Neither of these is considered an auxiliary battery. Some diesels even have 2 alternators that work together to keep the batteries up.
As is the case with many ordinary single battery vehicles that have wide variations in battery location, auxiliary batteries can be mounted just about anywhere. Single battery vehicles might have the battery in the trunk, under the back seat, hidden in the wheel well in front of the left front tire, and other places.