Owing to the quarantine for the COVID-19 health emergency, the use of cars has drastically diminished. How can we protect the health of the lithium battery, key element of the electric car, which corresponds to about one third of the entire car value?
Lithium ion cells that make up the electric car’s battery lose their charge slowly, about 2% per month, then up to 15 km of charge per day.
EV battery packs, anyway, should be maintained neither at 100% of the charge nor close to zero because the stress on cathode materials would increase and a battery, if left discharged for a long time, might even be damaged irreparably.
The ideal would be to keep it at a constant charge level included between 50 and 80% of the capacity. Then, the car that stands still, like in the lockdown case, should be anyway recharged once a week to restore about 80% of the charge and, once reached that level, we should disconnect it.
However, we must take care of the accessory battery, too: in addition to the traction battery pack, each EV is also equipped with the standard 12-volt accessory battery that operates other electrical components, like windscreen wipers and lights. Therefore, also the accessory battery needs care and must be connected to a specific battery charger every now and then.