Prepare the car in this order instead of chasing a universal battery percentage
- 01Read the storage section for your exact model
Manufacturers differ on preferred state of charge, whether the car should stay connected to external power, how long it can remain parked, and what happens to the 12-volt battery. Use the instructions for the specific model year rather than advice from another EV brand.
- 02Set the charge limit or target the recommended storage range
If the vehicle provides a charge-limit setting, use the manufacturer’s storage guidance instead of automatically leaving the battery at 100 percent. Likewise, do not intentionally park the car nearly empty unless the manufacturer specifically directs that procedure.
- 03Decide whether the car should remain plugged in
Some vehicles are designed to manage the battery while connected and others give different storage instructions. Confirm outlet, EVSE, weather, parking, and electrical safety before leaving a charging setup energized for an extended absence.
- 04Reduce unnecessary wake-ups
Frequent app checks, third-party telemetry services, cabin preconditioning schedules, sentry or security features, and always-on accessories can increase energy use on some vehicles. Keep the features you actually need and disable only those the vehicle documentation says can be changed safely.
The high-voltage battery is only one part of the storage checklist
- Set cold tire pressures to the vehicle placard specification before the car sits
- Remove food, trash, and anything that can attract rodents or create odors
- Unplug unnecessary 12-volt accessories such as dash cameras or USB devices if the manufacturer permits it
- Confirm how the vehicle maintains or does not maintain its 12-volt battery during storage
- Avoid leaving the car where standing water, extreme heat, flooding, or deep snow can create access problems
- Do not leave a charging connector arrangement exposed in a way the charger or vehicle manufacturer prohibits
- Keep enough key-fob access and account information available for the person who may need to move the vehicle
Three common storage approaches can all be wrong for the wrong vehicle
Energy use from vehicle systems still varies. Know the expected parked consumption and 12-volt behavior instead of assuming the battery percentage will not change.
The electrical installation and parking environment must also be appropriate for unattended use. A charge limit is not a substitute for a safe circuit and compatible EVSE.
Give that person the correct charging procedure and do not ask them to improvise with adapters, extension cords, or unfamiliar jump-start points.
The 12-volt battery can still be the part that prevents the car from waking up
Most EVs still rely on a low-voltage battery to power computers, locks, contactors, and other systems needed before the high-voltage pack can operate the car. A traction battery with plenty of indicated range does not guarantee the 12-volt system will be healthy after a long storage period.
How the high-voltage system supports the 12-volt battery varies by model. Some vehicles periodically maintain it under certain conditions, while others have specific storage procedures or limits. That is why a generic trickle-charger recommendation should not be attached to every EV. Use only charging or maintenance equipment and connection points approved for your vehicle’s low-voltage battery type.
When you return, inspect the parking area, tires, charging cable, and underbody before immediately accelerating away. If the vehicle reports battery, isolation, charging, or high-voltage warnings, follow the manual and service guidance rather than repeatedly power-cycling the car to clear them.
Safety check
Do not copy another EV owner’s storage percentage as a rule for your car
Battery chemistry, thermal management, software, 12-volt strategy, and manufacturer recommendations differ by model and can change by model year. The correct storage target and plug-in procedure should come from the documentation for your vehicle.