What is an auxiliary battery?

While the primary focus of EV development often revolves around the propulsion battery, auxiliary batteries play an indispensable role in powering non-propulsion systems. From supporting safety features and infotainment systems to ensuring vehicle operation and redundancy, the auxiliary battery is an unsung hero in electric vehicle design.

How do auxiliary batteries work?

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.

Why do electric vehicles use auxiliary batteries?

Electric vehicles still consume power when idle. Climate control, keyless entry systems, alarm systems, and internet connectivity all draw small amounts of power when the vehicle is not in motion. The auxiliary battery handles these power draws, ensuring that the primary propulsion battery retains its charge for driving.

Does a car have an 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.

How are auxiliary batteries charged?

Instead of using an alternator to charge the auxiliary battery like gas-powered vehicles do, auxiliary batteries in HEVs and EVs are recharged by the HV battery using an inverter/converter. Batteries in gas-powered vehicles are charged via the engine and alternator.

Why should you use an auxiliary battery?

By using an auxiliary battery, you can ensure uninterrupted power supply and maximize the performance of your devices and systems. The main application of an auxiliary battery is to act as a backup power source in case the primary battery fails or is unable to provide sufficient power.