“You can’t treat cars like people. Cars need love,” said Walter Röhrl – and this is true even in the modern electric era. Electric cars are often thought of as ‘maintenance-free’, yet if you treat them with care, they will last longer. And this also applies to charging.

How often to charge

You may be used to filling up your combustion car, then driving and driving until a hungry eye blinks at you, filling up and driving and driving. But this is not an ideal approach for an electric car, because fully charging or completely discharging the batteries is not very good (we will talk more about this in a moment), at the same time it is also time-inefficient (the entire charging process is a longer matter).

It is equally inefficient to constantly charge to full for fear of limited range, because as we said last time, above the 50% charge level, and especially above 80%, the charging speed decreases. On long journeys, it makes sense to approach “zero” (actually more like 10% to make sure you don’t get stuck anywhere) and charge the energy on a DC/HPC fast charger only for the last few tens/hundreds of kilometers to the destination, which can take you 10-30 minutes (just to go to the toilet, buy a coffee and check the news on social networks), where you will recharge comfortably and cheaply with a slower current (AC).

Foto: Hyundai

You complete a full charge cycle (10-80%) only on really long journeys, in reality you usually only charge a few tens of percent, which takes less time than how long it takes you to jump to a gas station and buy a coffee.

So, from a practical point of view, and also for the best battery health, it’s most efficient to hover between 20-80% charge level – which, depending on the range of your electric car and how much you drive each day, means charging maybe once a week in a full cycle. But this does not mean that you will have to sit at the charger for an hour, you can charge overnight at home or perhaps combine it with a visit to a shopping center or fast food.

With the increased availability of charging infrastructure, you will probably charge more often and in smaller “batches” in the future – for example when you go shopping or go out to dinner at a restaurant or when you are at the cinema or perhaps in the gym, i.e. in places where your car would just sit idle anyway parked. You simply connect the cable for a few (dozens) of minutes and while you do something else, your car will be charged by just a few tens of percent, which will ensure you another few days of carefree operation. You won’t have to plan it, it won’t bother you or delay you. You just need to change your thinking a bit, but that will come naturally as you naturally use the electric car, learn to live with it and stop being afraid that you only have a third of the battery left (which can still be over 150 kilometers that cover three days your commute).

How to charge safely

First of all, let’s say that there is no major danger when charging – unless there is a technical fault in the electrical wiring of the charger or in the battery of the electric car. However, the battery of an electric car is subject to chemical and physical laws, which must be respected during use. With a mobile phone, you don’t mind so much that it will be thrown away in two years, but with an expensive electric car battery, you would definitely want the longest possible lifespan. So how to achieve it?

Foto: Hyundai

The most convenient, economical and cheapest way to charge is at home via an AC wallbox. But you can also use public AC chargers when your car is parked idle while you shop at the mall, have lunch at a restaurant or watch a movie at the cinema.

Thanks to intensive technical development, modern Li-ion batteries are much more durable than batteries of the past, but it is better to follow simple principles. The most common batteries with NMC chemistry (nickel-manganese-cobalt) do not like to be discharged to zero or charged to full – that is also why they are equipped with a protective buffer (reserve capacity), so discharging to zero means for the battery a discharge of (for example) to 5% and charging to it is actually only 95% full. Nevertheless, you should try to stay within the already mentioned range of 20-80%. Before parking the car for a long time, it is better to leave a little more energy in the battery (Li-Ion batteries are stable by themselves, so they do not self-discharge, but they can recharge 12V batteries with their energy so that they do not discharge), but do not charge it to 100% . It only makes sense to use the full capacity when you are going on a long journey and need maximum range.

Batteries with LFP (lithium-iron-phosphate) chemistry, which are now gradually entering the market, are then even more durable and suffer less from extreme charge/discharge conditions. So you don’t have to worry about running them down to zero (if you’re not afraid that it won’t work out and you’ll be stuck somewhere) or charging them to full (some of them even require this from time to time for calibration). And because they have a lower energy density, they are used more for battery packs with a smaller capacity – it’s just right that you can use their full capacity more often (but you can easily stick to the principle of charging more often in a smaller range, that’s for the health of the battery after all more favorable).

Foto: Hyundai

Electric cars use Li-Ion batteries, but their chemistry can vary and each has its advantages and disadvantages.

On the contrary, you don’t have to worry too much about fast charging. Practice shows that charging at a higher power has less effect on the health of the battery than the just-mentioned discharging and charging to extremes. The advantage in this case is the 800V architecture (currently used by Hyundai and Kia electric cars, or the Porsche Taycan and Audi e-tron GT twins), which uses lower charging currents compared to the commonly used 400V architecture – in addition, it enables high charging powers (instead of 200 kW up to 350 kW).

Tested on the road

These findings are confirmed by doc. Ing. Tomáš Kazda, PhD., who is engaged in research and development of materials for batteries at BUT. In cooperation with Petr Beneš, another electromobility expert, they checked the SoC (state of charge) of two first-generation Hyundai Ioniq cars with over 200,000 kilometers of mileage in an independent test, and both showed a capacity degradation of only around 4%.

Photo: Petr Beneš

Experience from the long-term operation of an electric car confirms that fast charging has less effect on battery health than discharging to zero and charging to a hundred.

Service and recycling

From the point of view of regular service, the traction battery is practically maintenance-free, however, like any car part, it wears out over time (degradation of capacity) or one of the cells may be damaged. In this case, the whole battery is not worth several hundred thousand to throw away, only one of the many modules (10-30 depending on the battery design) is changed – which is no more expensive than, for example, replacing the turbocharger, injection or catalyst in a conventional car.

However, in contrast to a car with an internal combustion engine, it is much easier to find out the actual “health” of the battery in a used electric car – basic information will be given by diagnostics after connecting to a computer, further details will be revealed by a stress diagnostic test. In short, you always know exactly in what condition you are buying a used car. In contrast to general prejudices, electric cars can therefore have a longer life than cars with an internal combustion engine, which after driving some 200,000 kilometers, no one really wants to buy anymore, because they know very well that there is a ticking time bomb under the hood, which can explode very unexpectedly – and expensively. in the face.

Foto: Hyundai

An electric car can help you create an energy self-sufficient household. An old battery (or even the battery of an electric car that you normally drive) can store excess energy from solar panels or you can charge it cheaply with night current, on the contrary, it supplies energy to households during peak energy times.

And what will he do?

When the battery’s capacity drops to about 60% and its range is no longer sufficient for the car owner, a second life awaits it in the form of battery energy storage. You can hang it on the wall at home and charge it cheaply with night current or for free from solar panels, then you can discharge it during the day during energy peaks, when current is more expensive. When it has served here as well, it will be time for recycling. In laboratory conditions, it was possible to achieve a level of recycling approaching 100%, and the yield of recycling lines could then reach up to 90%.

Automobile companies offer an 8-year warranty (or 160,000 km) for their car batteries, after which they guarantee 70% capacity, but practice shows that some vehicles may still have 95% of their original capacity after 200,000 miles. It really depends on how you treat your car. Just as with an internal combustion car it was worth treating it with additive fuels and going for regular oil changes, so too electric cars will reward you with a long life for a higher level of care (more frequent slow charging and maintaining the state of charge in the range of 20-80%). There is really no reason to be afraid of electric cars.