An auxiliary battery, also known as a secondary battery, is an additional battery that is installed in a vehicle to provide power to various electrical components.
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.
When the main battery is connected to the auxiliary battery, it charges the auxiliary battery through a charging system. This charging system typically consists of an alternator and a voltage regulator. The alternator generates electricity while the voltage regulator controls the amount of voltage supplied to the auxiliary battery.
Modern vehicles with CO2 reduction technologies, high levels of specification, and new electronic driver aids may feature an auxiliary battery alongside the main vehicle starter battery or high voltage system battery on Hybrid and electric vehicles.
What is the difference between auxiliary battery and main battery?
While the main battery powers the starter motor and provides the initial electrical energy to start the engine, the auxiliary battery is responsible for powering other electrical components and systems in the vehicle. How Does an Auxiliary Battery Work?
Can auxiliary battery be connected to main electrical system?
During normal operation, the auxiliary battery remains isolated from the main electrical system, preventing any drain on the main battery. However, when the vehicle is not running or the main battery fails, the auxiliary battery can be connected to the main electrical system to power the necessary components.
Auxiliary batteries, like your main battery, need to be checked regularly for corrosion, damage and leakage. Depending on the location of the battery, this could be difficult for you to do yourself and you may require the assistance of a mechanic. What Are the Signs of a Bad or Failing Aux Battery?