Can You Store An EV Away For Years But Still Drive It?
Barn find is a term used to describe the act of one stumbling upon an abandoned vehicle, usually of immense value, left to rot for decades in a shed or a garage. Social media sites are littered with stories of people unearthing classic or muscle cars that have been neglected for decades.
Surprisingly, with a little bit of work on the fuel system and replacing the 12V battery, these vehicles spring to life. What if an electric vehicle were stored for months or years without being charged, would it still be drivable like internal combustion engine vehicles?
That really depends on several factors. EVs rely on two electric systems to function, a low volt one that uses the 12V battery for the infotainment system, doors, A/C and various other accessories. Then there’s the high voltage system that gets power from the battery pack, which is used to power the vehicle’s electric motor.
Like a regular ICE vehicle, if an EV is left unattended for several months, it would probably need a new 12V battery. Due to phantom drain or age, the charge would probably drop to an extremely low level. The beauty of this lead acid battery is that it can still be brought back to life with a proper charger. But this depends on several things including internal chemistry and age.
An EV’s actual large battery pack consists of hundreds if not thousands of lithium-ion cells. They are the preferred choice because of being able to deliver high voltage, low discharge rate and high energy density characteristics.
But the problem with lithium-ion cells is that they are temperature sensitive and as such need to be kept within a narrow temperature window to deliver the required electricity. Keeping it within 21 to 25 degrees Celsius ensures good battery health and optimal power delivery.
This is why all EVs have a battery management system (BMS) that monitors the state of charge, supply from the charger, temperature, and various other metrics to keep the vehicle working at its best. There are several measures that can be taken by an EV owner to reduce overall battery drain. They can choose to turn off certain monitoring systems that take up a considerable amount of power.
BMS remains operational throughout the vehicle’s life, keeping a watchful eye on the battery pack. Various systems like this contribute to phantom power drain in EVs. On average, they can lose about 2 to 3% of their charge if not used for a month.
If the EV had about 60 to 80% of its original charge at the beginning, theoretically, it could be left for several years and still have enough charge to power up the vehicle and drive it away. A problem arises if it only had 5 to 10% of charge and was moved into storage.
Over a month or year, that state of charge could be reduced to a very low level. Lithium-ion cells can only be depleted to between 2.4V to 3V. Any lower and they could face internal damage. That’s where the BMS’ importance comes in to shut down the individual cells to protect them from such an issue.
That’s why EVs cannot be locked away in barns indefinitely without the battery pack experiencing some form of damage. And since it makes up about 20% to 40% of an EVs value and determines the usefulness, a damaged battery pack will render an electric vehicle worthless.
