Do Electric Cars Lose Battery Power When Powered Off, Parked, and Doing Nothing?

Many drivers are intrigued by the fuel savings they could gain by purchasing an EV, but they’re wary of electric vehicles’ reliability. One worry is whether the battery could lose charge when the car remains parked for extended periods. Let’s take a closer look at whether that concern is justified.

How long can an electric car sit without charging?

Porsche Taycan electric car EV battery
A Porsche Taycan parked in front of a home | Martyn Lucy/Getty Images

Plugin Report has broken down the stats behind this question and filled us in on important information for anyone wondering how long they can let an EV sit without charging. It all comes down to how much charge the battery has to begin with.

With battery power at around 50%, expect an EV to be able to sit for months without the need for a charge, making you unlikely to find yourself with a dead battery if you haven’t driven your electric car for a while. But leaving your EV sitting with battery power that’s exceptionally high or low could more likely damage the battery cells. 

One additional factor you’ll need to keep in mind is the weather. If you live in a hot region, don’t forget that exposing your EV to temperatures above 100 degrees Fahrenheit could cause the battery to lose charge more quickly. 

EVs lose minimal battery power when parked

If you’re concerned about the possibility of your EV losing significant battery power over time, you can put those concerns aside. Consumer Reports explains that batteries undergo minimal loss of charge over time.

If you’re looking for specific numbers, you can expect an average EV battery to lose around 2.3% of its starting range per year. That means, for example, a Nissan Leaf with a starting range of 149 miles could expect to see a range of around 132 miles after five years. 

Clearly, at that rate, it would take many years for an EV owner to notice a significant drop in their battery power, no matter how much they drove the vehicle (or left it parked). 

Tips to maintain electric vehicle battery reserves and health

If you want to keep your electric car battery in tiptop shape, you can do a few things to help, according to CarProUSA. First, you’ll want to ensure that your 12-volt battery stays charged and that your high-voltage battery maintains a charge of at least 10%. 

Your 12-volt battery should stay sufficiently charged as long as you have charged your vehicle and/or driven it for at least eight hours in the past month. If you plan to go longer without doing either of those things, you’ll want to follow other steps to maintain your 12-volt battery’s health. 

If you go more than a month without driving your vehicle, your 12-volt battery could lose a significant amount of charge. To prevent that from happening, you should disconnect the battery’s negative terminal. If you’re unsure how to do that or don’t feel comfortable doing so, you have a couple of other options. They include leaving the vehicle plugged in if it’s a plug-in hybrid or all-electric, or connecting your 12-volt battery to a standard 12-volt battery charger and leaving it on a continuous slow charge. 

To ensure you do everything correctly and avoid mishaps, it’s always best to consult with a mechanic familiar with EVs. 

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