What Is ‘Vampire Drain’ and How to Minimize Its Impact

“Vampire drain,” also known as “phantom drain” or “parasitic drain,” refers to the gradual loss of an electric vehicle’s (EV’s) battery charge while the car is parked and not in use. This phenomenon occurs because various electronic systems in the car continue to draw power even when the vehicle is off. Here are some common causes of vampire drain:

1. Battery Management System (BMS): The BMS monitors the battery’s status, including charge level and temperature. It requires a small amount of power to operate.
2. Telematics Systems: Many modern EVs have built-in connectivity features for remote monitoring, updates, and diagnostics. These systems often remain active in a low-power state, consuming some battery charge.
3. Security Systems: Alarms, keyless entry systems, and other security features can draw power to remain functional.
4. Temperature Management: In extreme weather conditions, the vehicle’s systems might draw power to maintain the battery’s optimal temperature, particularly in EVs with active thermal management systems.
5. Periodic System Checks: Some EVs perform regular system checks and diagnostics even when not in use, which can consume small amounts of power.

Impact of Vampire Drain

The impact of vampire drain varies depending on the vehicle’s design and the systems that remain active. For most EVs, the drain is relatively minor, often only a few percentage points of the battery’s charge per day. However, over extended periods, especially if the vehicle is left unattended for weeks or months, this drain can become significant.

Minimizing Vampire Drain

To minimize vampire drain, EV owners can take several steps:

• Turn Off Unnecessary Features: If possible, disable features like remote monitoring if they aren’t needed.
• Use Energy-Saving Modes: Some EVs have specific settings to minimize energy consumption while parked.
• Keep the Vehicle Plugged In: When practical, keep the EV plugged into a charger to maintain the battery’s charge level.
• Check for Software Updates: Manufacturers may release updates to reduce the energy consumption of systems while the vehicle is off.
  
  

THE TAKEAWAY

Overall, while vampire drain is a normal characteristic of EVs, it is generally a manageable issue and rarely causes significant inconvenience for most users.

Sources: EV Car Answers Editors, ChatGPT, Polestar