How long can an EV sit? Storage charge level and the 12-volt battery, by the manual

The short answer: don't let it sit near empty, then follow your manual

An EV slowly loses charge even when it is parked; Polestar and Kia both say so in their owner's manuals. The risk is letting the battery drain all the way down. Polestar recommends charging whenever the level is under 20%. Nissan's LEAF manual says not to leave the car for more than 14 days with the charge gauge at or near zero.

For longer breaks, manufacturers disagree. Polestar recommends 40 to 60% for parking longer than a month and warns that holding a very high charge for a long time can damage the battery. Kia's US manual for the 2024 EV6 says to charge the battery once every three months during an extended break and to charge it to full capacity before storing it if the charge is insufficient. Your own manual is what counts.

The small 12-volt battery is the more common problem. EVs have one just like gas cars, AAA notes, and if it dies the car needs a jump. More on that below.

Sources: [1], [2], [4], [7]

Charge level: what the manuals recommend

The table sums up the manual pages we read. Polestar explains its advice with both extremes: a fully drained battery can be severely damaged, and so can a very high charge held for a long period. Kia's US EV6 manual adds that charging to 100% whenever the level is below 20%, at least once a month, keeps the battery in optimal condition, and warns that a battery kept insufficiently charged for a long time may degrade enough to need replacing. The German edition of the same Kia manual recommends charging only to 80% in daily use, so even editions of one manual differ.

If your manual says nothing about long-term storage, a medium charge level is the compromise Polestar's reasoning points to between deep discharge and a long-held high charge (our assessment). Check the charge level in the app now and then, as Polestar also recommends.

Sources: [1], [2], [3], [4]

The 12-volt battery: why a parked EV may not wake up

Every EV also has a 12-volt battery for the onboard electronics. AAA points out that it works just like the one in a gas car: if it dies, the car needs a jump start. In Germany, the auto club ADAC found in its 2026 breakdown statistics that a defective 12-volt battery was behind almost half of all its roadside calls, regardless of powertrain.

How much power a parked car draws was measured by ADAC in 2022 on 25 vehicles; the test does not say whether EVs were among them. Locked, the cars drew only 5 to 40 milliamps after about 25 minutes, which ADAC says a healthy battery can sustain for roughly two to twelve months. With the trunk left open, six of the 25 cars still drew up to 0.45 amps after two hours, enough to leave a car unable to start after five days. For storage of several months, ADAC recommends recharging the 12-volt battery regularly with a charger, following the owner's manual, because a deeply discharged battery can be permanently damaged.

Sources: [7], [5], [6]

Heat and cold while parked

Polestar advises plugging the car in whenever possible above 86 °F (30 °C) and parking in the shade, because the car otherwise cools the battery with its own energy and the charge drops. Where temperatures could reach about 131 °F (55 °C), it should not stay parked for more than 24 hours.

In the cold, Polestar says performance is reduced until the battery warms up, which does not harm it, and recommends plugging in if you park for more than 24 hours below −22 °F (−30 °C). Nissan says not to store the LEAF below −13 °F (−25 °C) for more than seven days.

Sources: [1], [4]

Checklist before a long break

The list combines the manuals we read and ADAC's advice. How battery coverage works if something does go wrong is explained in “EV battery warranty 2026: what 12 automakers cover in the US and what can void it”; what to check on a used car's battery is in “Buying a used EV: verify the battery, charging and paperwork”.

1. Look up what your manual says about long-term parking and set the charge limit in the car or app accordingly.
2. Never park near empty; charge first if the level is under 20%.
3. Leave the car plugged in with a charge limit if your manual recommends it.
4. Lock the car, close the doors and trunk and switch off the lights.
5. For several months, recharge the 12-volt battery with a charger as your manual describes, or ask someone to drive the car.
6. Choose shade or a plug in summer heat and a garage in winter.
7. Check the charge level in the app from time to time.

Sources: [1], [2], [5]