How to Store an Electric Car for 30–90 Days: Battery and Charging Guide

Quick answer: To leave an electric car parked for 30 to 90 days, follow the exact model’s long-term storage instructions, protect both the high-voltage traction battery and the low-voltage accessory battery, choose a safe parking location and check the charge level periodically. There is no one battery percentage or charging rule that applies to all EVs. As concrete examples, the 2025 Ford Mustang Mach-E owner’s manual specifies approximately 50% state of charge for storage exceeding 30 days for both the referenced NCM and LFP versions, while Tesla recommends leaving a Model 3 plugged in when not in use with the vehicle’s recommended charge limit set.

This is a practical checklist for holidays, seasonal storage and extended business travel. It explains why parking an EV at 0% can be harmful, what happens to the 12 V battery, whether to leave a charger connected and what to check before driving again. These are manufacturer examples, not a claim that every EV should be stored at 50% or permanently connected.

What battery percentage is best for long-term EV storage?

Source: Ford 2025 Mustang Mach-E battery care and extended storage instructions; Tesla Model 3 charging instructions.

Why the difference? Vehicle software, battery chemistry, charging management, low-voltage architecture and manufacturer recommendations are not identical. Long-term storage also differs from a normal daily charging routine. Ford’s cited LFP guidance specifically illustrates this distinction: a manufacturer may recommend one charge behavior for regular use and another for extended parking.

Can you leave an electric car plugged in for three months?

For a Tesla Model 3, its owner’s manual says Tesla strongly recommends leaving the vehicle connected when unused. Tesla explains that, while plugged in, the car can draw energy from charging equipment and periodically replenish charge to the programmed limit as needed. Tesla’s official travel guidance also says the vehicle is designed to maintain the battery when plugged in for an extended period.

That does not mean a homeowner should ignore the condition of the outlet or charging equipment. Charging requires a properly installed, undamaged charger and an electrical circuit appropriate for continuous use. Avoid unapproved extension cords and faulty outlets. The ability to leave a vehicle plugged in can depend on the vehicle maker’s instructions, site access and local electrical safety rules.

In contrast, Ford’s linked 2025 manual explicitly focuses on achieving the correct stored state of charge for an extended stay; always consult any additional low-voltage and storage procedure for the exact vehicle. For basic electrical safety, see our regular-outlet charging guide and EV charging troubleshooting guide.

What happens to the 12 V battery while an EV is parked?

Most EVs have a separate low-voltage battery for electronics, locks, controllers and other functions. They may occasionally use energy from the main traction battery to maintain it, depending on the vehicle. A high-voltage battery showing usable charge does not guarantee the low-voltage system will always remain healthy during extended parking.

The U.S. Department of Energy’s EV component overview describes the auxiliary battery and a DC/DC converter that uses traction-battery energy to support lower-voltage systems. Tesla’s high-voltage battery guidance warns that deep discharge can damage components, including the low-voltage battery, and may require service or recovery.

Never disconnect a low-voltage battery as a generic storage trick. Some vehicles have manufacturer-specific procedures; incorrect disconnection may affect locking, alarms, charging, warranty conditions or electronics. If your maker instructs low-voltage battery maintenance or disconnection for extended storage, follow its prescribed steps or use a qualified service technician. Our EV 12 V battery recovery guide covers common warning signs.

EV long-term storage checklist: before you leave

1. Read the correct manual. Confirm model year, battery chemistry, software version and market. Battery-care instructions can differ between variants.
2. Set the appropriate charge level. Use the maker’s long-term storage recommendation, not a blanket “always 100%” or “always 50%” rule.
3. Confirm safe charging equipment. If the car should remain plugged in, check that the outlet, EVSE, cable and connector are undamaged and suitable for continuous service.
4. Choose a safe parking spot. Prefer a secure, ventilated, flood-safe location; consider extreme heat and cold. Ford’s cited manual identifies a beneficial high-voltage battery storage temperature range of 0–45°C (32–113°F), but this is not a universal garage requirement.
5. Check tires. Inflate to the model’s cold pressure specification, inspect for damage and plan to reassess pressure after storage. Do not exceed the vehicle placard’s values simply to prevent flat-spotting.
6. Turn off unnecessary high-drain functions where appropriate. Review vehicle-specific cabin climate, security recordings and frequent remote polling settings; availability and power draw vary.
7. Secure keys and access. Verify the vehicle is parked safely, charging status is as intended, and you can access the account and roadside service if needed.

If parking on a property where others may need to access the vehicle, provide appropriate authorized instructions without leaving security credentials exposed.

If the EV is stored unplugged, how much charge will it lose?

There is no dependable universal self-discharge number. Loss shown on the vehicle display can include climate management, low-voltage support, connected functions and periodic system activity, not just lithium-ion cell self-discharge. A car in winter or extreme heat may behave differently from one in a temperature-controlled garage.

As an example of illustrative arithmetic rather than a manufacturer prediction, if the displayed battery level fell by 1 percentage point every five days, it would drop about 18 percentage points during 90 days (90 ÷ 5 = 18). Your vehicle may lose far less or substantially more. Do not use this hypothetical estimate to decide whether an EV can safely be left at a low state of charge.

If you cannot keep the vehicle connected, consult the exact manual for the initial state-of-charge target and for appropriate periodic checks. Avoid leaving the battery near empty. Our parked EV battery-drain guide</a explains why consumption can continue when the car is not moving.

Do not confuse an emergency evacuation charging recommendation—where extra range may be valuable before a storm—with a long-term storage target. If flooding or fire threats are present, personal safety and local emergency advice take precedence. Read our daily 80% versus 100% charging guide for the separate everyday-use question.

What to check after 30–90 days before driving again

After long storage, do not immediately begin a demanding trip without confirming safe operation. A dashboard error, physical damage or a dead low-voltage system deserves model-specific service guidance rather than improvised high-voltage repairs.

Official sources and limitations

Checked November 7, 2026: Ford 2025 Mustang Mach-E owner’s manual, storage state of charge; Tesla Model 3 charging instructions; Tesla long-absence charging advice; and DOE: Battery-electric vehicle components. Battery chemistry, charge management and manufacturer guidance vary. This article does not promise that storage is risk-free.