Electric car maintenance: what to do to extend the life of the batteries?

With significantly fewer moving mechanical parts than an internal combustion engine vehicle, operating an all-electric car is much simpler and cheaper. Here are the calculations of the French car manufacturer Citroën, according to which the operating costs of an electric car can reach up to 30%. smaller than the same model with petrol or diesel engine.

Despite the simpler maintenance, it is not uncommon for motorists and those looking to purchase a clean vehicle to have questions related to operation, including the costs of daily use, charging times, optimizing energy consumption and, ultimately, extending the battery life of an electric car.

It is important to monitor the charge level

All electric car manufacturers, in addition to lower costs of daily use and maintenance, can offer another serious advantage: an exceptionally long battery warranty period, which very often exceeds that provided for traditional cars.

Currently, many manufacturers offer a full 5-year or 100,000 km warranty on cars powered by internal combustion engines. This warranty, which has become a global standard, is what every new car buyer expects.

In turn, electric car manufacturers provide a warranty of 8 years or 160,000 km for the main battery. Some manufacturers supplement its conditions with another point: the remaining capacity of the battery. For example, the battery of the fully electric Citroën ë-C4 comes with a standard warranty and, at the same time, the manufacturer undertakes to ensure that after eight years or 160,000 km the battery capacity reaches at least 70%. initial capacity.

However, to ensure that the retained useful capacity of the battery after a few years or several tens of thousands of kilometers is perhaps even higher, electric motorists can take fairly simple measures themselves.

Donatas Kriaučiūnas, professor at the Department of Automotive Transport Engineering at Vilnius University of Technology and Design, assures that three factors have the greatest influence on the longevity of an electric car’s battery: the maintained charge level, charging power and temperature regulation.

“The most important factor that depends on the driver himself is the correct charging and discharging of the battery,” says the specialist. “Electric car manufacturers often indicate the number of full charge and discharge cycles (100% – 0% – 100%) that will reduce the battery capacity. Maintaining the battery charge level between 40 and 80% will prolong the life of the battery,” says the specialist.

It should not be completely drained

D. Kriaučiūnas also emphasizes that to maintain maximum battery performance, it should not be completely discharged.

“Cases of complete battery discharge are rare, but can occur when an electric car is not used for a long period. Manufacturers indicate that, to preserve the “life” of the car’s components, the battery charge decreases by about 1% per day even when it is not used. Therefore, before parking the car for a longer period of time, it is necessary to evaluate it and make sure that the battery is sufficiently charged,” adds the specialist.

According to him, whether an electric car’s battery will last a long time can also be determined by its charging capacity. According to the interviewee, frequently charging the battery to maximum capacity can shorten its life.

However, he adds, depending on the battery management system, this effect is almost eliminated, as charging capacity is limited when the battery is cold and approaching 100%. load level.

“The increased wear and life of the battery is determined by the rate of discharge of the battery. Even electric car manufacturers indicate that, especially during rapid acceleration, the battery discharges at a rate 2, 3 or even 6 times higher than the nominal capacity of the battery,” emphasizes D. Kriaučiūnas.

Battery performance may decrease in winter

When the temperature drops below freezing, weak points in cars often emerge, and electric cars are no exception. According to D. Kriaučiūnas, the capacity and performance of the battery may decrease when using the car in negative ambient temperatures, but this is more related to the design of the battery.

Although battery temperature regulation, as the expert calls it, can affect its longevity, the driver will not do anything in this case, because the temperature regulation systems are taken care of by the manufacturer. When designing the car, predict how the battery’s optimal temperature will be maintained: whether it will be cooled by counterflow air, air from inside the car, or whether the battery will have a separate air conditioning system.

“If the battery is equipped with a temperature regulation system, this effect is minimal, because during vehicle operation the battery temperature is kept within the limits specified by the manufacturer, but the battery energy is used for this and the battery discharges faster,” explains D. Kriaučiūnas.

Car manufacturers use different technologies to maintain the optimal temperature of the battery: a heat pump, a tank with an electric coil immersed in a liquid or, as in the electric Citroën ë-C4, a combination of both technologies. The battery of the car from the French manufacturer is liquid-cooled, but at the same time the electric car is equipped with a heat pump with a power of 5 kW and a standard PTC heating element, also with a power of 5 kW.

“Batteries without a temperature regulation system suffer greater energy losses at both high and low temperatures, because the optimal operating temperature reduces their capacity and the amount of energy that can be released. When operating in such conditions, the capacity and performance of the batteries decrease faster than models with a temperature regulation system,” adds D. Kriaučiūnas.