An electric car's battery will hold its charge for a surprisingly long time when parked, typically losing only about 2-5% of its charge per month. The exact duration depends heavily on factors like the battery's size, the outside temperature, and whether certain power-draining features are left on. For most owners, this means you can leave your EV parked at an airport for a week or two and return to find it with nearly the same charge level.
The biggest factor affecting charge loss is temperature. In cold weather, the battery management system (BMS) must work to keep the battery within a safe temperature range, which uses energy. In very hot climates, the BMS may also activate cooling. This "vampire drain" is more pronounced than in mild conditions.
Another key factor is vampire drain from connected features. If you leave your car's app-connected services, Sentry Mode (a security feature that uses cameras), or cabin pre-conditioning scheduled, the battery will deplete much faster. For example, leaving Sentry Mode on can drain several percent of your battery per day.
For long-term storage, the best practice is to leave the EV plugged in, if possible, and set a maximum charge level of around 50-60%. This minimizes stress on the battery. If unplugged, aim to store it with a charge between 30-50%.
| EV Model | Estimated Monthly Standby Drain (Ideal Conditions) | Key Factors Influencing Drain |
|---|
| Tesla Model 3 Long Range | ~2-3% | Sentry Mode, Cabin Overheat Protection |
| Ford Mustang Mach-E | ~3-4% | Connected Vehicle Features, Temperature |
| Chevrolet Bolt EV | ~2% | Minimal connected features, stable battery |
| Hyundai Ioniq 5 | ~3-5% | Battery conditioning in extreme temps |
| Nissan Leaf | ~4-6% (varies by model year) | Lack of active thermal management |
