How to preserve an electric car battery: the good practices
In the midst of climate change, consciences are also converging. Ecology is of course not always the main motivation of every electric vehicle owner, but all the statistics tend to highlight that electric cars are no longer science fiction nor utopia, but a reality today.
I have an electric car, and now what?
You just bought an electric car and probably your car-dealer doesn’t knows what this means really in a day-to-day practice, for a new user like you.
So here you are at home with a new electric car which will necessarily require to recharge its battery.
It is very likely that nobody has given you any recommendation for this recharge, a bit like when you buy a mobile phone.
For this reason, we gathered the following tips, in order to help you keeping your battery in top shape as long as possible.
What is the SOH?
You might ask yourself what are these new incomprehensible words probably created by experienced “geeks” …
Well, if you take a closer look, you’ll see that it’s not as complicated as that.
SOH stands from State Of Health, which simply qualifies the health condition of your electric vehicle’s battery.
The intention is to preserve this SOH at 100% for as long as possible, so that your electric car keeps its operating range like when it was new.
Obviously, the SOH will likely degrade a little bit, but the tips below will help you keeping it high for a longer time.
Do not keep your EV's battery charged at 100% for long periods
The ideal state of charge for preserving an electric vehicle’s lithium battery is between 20 and 80%.
It is within this charge range that the battery’s chemistry is stored the best. In most cases, a recharge of up to 80% will be enough for daily trips, while charging to 100% will probably only be useful for weekend or holidays journeys.
During the public confinement period for instance, imposed because of the Covid-19 and the novel Coronavirus, it is more interesting to leave your electric car charged at 60% of its capacity.
This is the level of charge at which the battery will be the best preserved from wear, during long periods of immobility.
Charge your battery at 100% just before to leave
Preferably, you should charge the car’s battery to 100% just before going for a long journey, so that you can leave as soon as it is charged.
Small daily trips can be made withing the range of 20 and 80%, and you will mainly charge up to 100% for the weekend or just before a long trip.
Do not worry about limiting this maximum charge state, as modern electric cars allow you to set the level to reach (80% in this case) before stopping the process automatically.
If you have an older electric car that does not have the feature for stopping the charging process at a certain percentage, it will suffice to use a timer switch to avoid reaching 100%.
Limit the number of fast charges
It is the case with almost any rechargeable battery today: the slower it is charged, the better it is.
You should know that a fast charge, like the ones available at the stations along motorways, tends to heat the battery’s cells.
Of course, most car manufacturers have equipped their electric cars with battery temperature control systems, to overcome this problem.
However, you should favor the slow charging which is usually performed at home or in the office, using a private charging wallbox station or a portable charger.
Fast charging must be left for long journeys only, when the time available is reduced and in order to not over slow down the trip.
Park your car in the shade
In case of hot weather, it is better to park your electric vehicle in the shade, especially during the charging process.
From time to time, charge your electric car's battery to 100%
Lithium batteries that equip the great majority of today’s electric cars are composed of multiple cells which are interconnected, in order to create the vehicle’s battery.
Depending on the car, we’re talking here about one hundred cells or even more.
In order to continue to operate in the long term without problems, these cells must be balanced.
This means that they must always be all at the same voltage. In other words, they must have the same level of charge.
Unfortunately, over the time, the voltage of these cells tends to evolve differently between them. So here comes the need to balance them.
The balancing process takes place at the end of the charging operation.
The battery management of your electric car will make sure to charge more the cells having a low voltage and less the ones that have their voltage higher. The aim is to have all of the cells at the same voltage level when the charging process ends.
This is the reason why the charging process of an electric vehicle usually slows down when it approaches the 100%: the balancing operation takes longer to achieve.
Concidering that the battery’s cells need to be balanced, it is necessary to charge your electric car up to 100% from time to time. This is typically something to avoid on the motorway charging stations because of the time that it requires. Fully charging an EV’s battery must be left for home or the office, when you charge with a private charging station or a portable EV charger.