The Fate of EV Batteries When Left for a Month-Long Vacation

KatadataOTO –  Many car enthusiasts or EV owners, whether of electric cars or motorcycles, wonder how long their vehicle's battery can hold a charge when left unattended. A common fear is returning after leaving the EV for a few days to find the battery depleted, which is certainly inconvenient, especially when far from a charging station.

Generally, batteries will lose power when left for some time. However, there isn't much information on how long the electric charge will remain in the battery.

Recently, or more precisely during last year's end-of-year holiday, a writer from InsideEVs conducted an experiment on their Kia EV6 electric car. Curious about the above, they left their electric car at home in the New York area from December 15, 2024, to January 10, 2025. 

For context, when the Kia EV6 was left, the owner had charged its battery to 80 percent with a range of 294 km. While it was left, the east coast of the United States, including New York, experienced very cold temperatures, averaging 0-12 degrees Celsius, with the coldest reaching around -11 degrees Celsius. 

Photo : Courtesy

After 28 days, upon returning home, the owner, who had not checked the car via the mobile app during the holiday, immediately performed a check. The results on the MID showed that their Kia EV still had a 78 percent battery charge with a range of 289 km.

This serves as a case study proving that an EV battery only experiences a 2 percent power drop when left for about a month. This includes its 12-volt battery. 

Claims from Hyundai and Neta in Indonesia

PT Hyundai Motors Indonesia (HMI) assures EV owners that they do not need to worry if they have to leave their car for a long time. The battery charge is guaranteed to remain stable or not drop; owners just need to pay attention to a few things to keep the car's systems functioning normally.

"Ensure the battery has a minimum charge of 50 percent when you plan to leave it. We also recommend storing the car in a safe location, away from direct sunlight or rain, to avoid extreme weather," explained Sugiartono, Head of Technical & Quality Management at PT HMI, to KatadataOTO.

Specifically, Ioniq 5 and all-new Kona users can monitor the vehicle and battery status remotely through the Hyundai Bluelink application. 

Photo : KatadataOTO

Meanwhile, Neta advises owners to focus only on the 12V battery. The goal is to ensure the car has no issues starting up again after being left for a long time.

"If owners plan to leave the car for more than 2 weeks, it is recommended to disconnect the negative and positive terminals of the 12V battery to avoid any starting problems. Meanwhile, based on the experience of Neta consumers, when the car is left for 4-5 days, the battery charge drops by about 2-3 percent," explained Januar Eka Sapta, After Sales Senior Manager at PT Neta Auto Indonesia, to KatadataOTO.