Car owners have always wanted to personalize their vehicles with extra lighting, upgraded audio systems, dash cams, or comfort‑related add‑ons. However,
unlike a petrol or diesel car, an electric vehicle (EV) is entirely dependent on electrical systems to operate. This naturally raises a concern about aftermarket accessories in the EV scenario and whether they can damage the expensive battery pack. The honest answer is that it depends on 'which battery' the accessories draw power from and how they are installed. An EV actually has two different batteries and understanding them is key to knowing what is safe. The Propulsion Battery (High‑Voltage Battery) This is the large lithium‑ion battery pack that powers the motor and gives the car its driving range. It usually operates between 300V and 800V, depending on the EV model. It handles propulsion, regenerative braking, and major systems. It is protected by complex electronics and managed by a Battery Management System (BMS). Directly tapping into it for accessories is unsafe and could void the warranty. The Auxiliary Battery (12V Battery) Even in EVs, a small 12‑volt battery exists—just like in traditional petrol or diesel cars. The 12V battery is responsible for powering low‑voltage systems like lights, infotainment touchscreen, locks, and sensors. Most aftermarket accessories (LED lights, dash cams, speakers) are designed for the 12V systems, which means they connect to the 'auxiliary battery', not the high‑voltage propulsion battery. Since these two batteries are separate, aftermarket accessories rarely come in contact with the propulsion battery, which greatly lowers the risk of damaging it. However, this does not mean that adding aftermarket accessories is completely safe and does not pose any risk to an EV. The 12V battery in EVs is often smaller in capacity than the one in petrol or diesel cars because the load on it is lighter. If you install accessories that draw more power than the 12V system can comfortably supply, you may face problems such as faster battery drain, reduced lifespan of the 12V battery, frequent error messages from the vehicle control unit and even failure of key systems, including lock-unlock or start-stop system. While it may not harm the propulsion battery necessarily, it can certainly cause inconvenience or require a 12V battery replacement. Also Read: I Want To Buy An EV From A Trusted Brand - What Are My Options In February 2026? In terms of the main battery, damage can occur after installing aftermarket accessories, in the case of someone attempting to connect high‑power accessories directly to the main battery, bypassing factory wiring and splicing into the main battery power wires. This can interfere with your EV's battery management system and lead to major malfunctions. It would also void your warranty, leading to highly expensive repair estimates. Hence, it is advisable to refrain from making any aftermarket upgrades to your electric car that have not been prescribed by the manufacturer. Making a small upgrade may improve your experience in the short term but it can lead to major malfunctions and steep repair costs in the long run.
