Electric vehicle batteries lose charge while parked

Electric vehicle (EV) owners may notice battery depletion even when the vehicle is turned off and stationary. This loss of energy is driven by two primary factors: natural battery self-discharge and the continuous operation of onboard electronic systems.

Lithium-ion batteries undergo a natural process called self-discharge due to internal chemical reactions, such as the oxidation and reduction of electrolytes. However, a significant portion of energy loss is attributed to active electrical architectures. Battery management systems (BMS) perform periodic health checks and use the high-voltage battery to recharge smaller 12-volt auxiliary batteries that power essential components like door locks, computers, and internal sensors.

Connectivity and security features also contribute to energy consumption. Technologies that allow drivers to remotely monitor vehicle status, adjust climate control, or prepare the cabin via mobile apps draw power. Additionally, surveillance systems, such as Tesla’s Sentry Mode or Rivian’s Gear Guard, require constant energy to operate cameras and sensors. Extreme weather conditions and frequent requests from third-party applications can further accelerate these energy losses.