Electric cars, a guide on how to recharge at home or in poles

How long Electric cars As it began to spread, a portion of the specialist press consciously or unconsciously conveyed the idea that to use a battery-powered car, you had to be an expert. On the one hand, we can definitely say that knowing technical terms isn’t a bad thing at all, which is why in this new episode of “Driving electric cars“We’ll talk about it. However, on the other hand, we need to dispel the myth and tell it like it is: recharging an electric car is as easy as recharging your mobile phone… It just takes a little longer because the battery is bigger…

important hypothesis

Reviews, data sheets, and ads are used to being targeted by numbers. “This electric vehicle recharges in 30 minutes thanks to direct current fast charging of up to 150 kW. This one, on the other hand, takes two hours alternating current three-phase poles ”… and so on. But do we really need to know all these terms? What does direct current mean? And what are kW? We’ve partly talked about that Here, in our dictionary of electric vehicle termsFor the rest, you’ll find useful definitions and explanations at the bottom of the page.

However, the answer to the question above is that we don’t need to know any of this. When I bought my first electric car, I didn’t even have to install one square wall Or a socket: To start, a very common three-prong Italian socket that was already installed in my garage was sufficient since the house was only about ten years old.

Some may object that it takes longer to recharge from a classic household socket, and this is true, but this does not mean that you need to “fill up” quickly: it all depends on your consumption and daily distances. If your electric car has a range of 300 km and you drive an average of 30 km per day, it is easy to calculate that you will have to recharge once every ten days. And here’s the first mistake: the previous statement is valid only for those who don’t have a trick in the box.

On the other hand, if you can top up in your garage (or in your villa driveway for the lucky ones), you have to get into the “add-up” perspective. Do you get home after shopping? Put the car inside the shipment. Do you go out for pizza in the evening? When you return you will put the car in charge, and so on…

This way you will never need to do a long, slow charge of 5, 10 or more hours because you will always be recharging. By analogy, imagine that instead of filling up 40 liters of petrol every week, someone, without you having to get your hands dirty, would go every evening to fill up the liters you had consumed during the day: not enormously more comfortable than going to the gas station on purpose And maybe standing in line at the always-crowded station that has the best fares in the area?

How do you calculate shipping times?

The formula for calculating charging times for your electric car is very simple, but you need to know some data:

– battery capacity, its unit of measure is kWh (eg 50 kWh)

– The maximum recharging power of the AC charger that your vehicle is equipped with. It’s usually 7.4 kW on older or cheaper electrics, or 11 kW. Some cars also have a 22 kW option.

– How to recharge the car: The local charger (which connects to the three-prong Italian plug) is usually up to 1.8 kW, with a maximum of 2.3 kW. On the other hand, if you install a wallbox, the maximum power is used by the meter. AC recharging is what we usually do at home or in public poles equipped with a Type 2 connector:

The latter usually has an output of 11 kW or 22 kW. DC charging is only available at public stations, which are larger than AC poles (they are similar in size to lockers). Features with this CCS Combo 2 connector:

Summary: Is there a CCS Combo 2 connector from the first picture? You are recharging in direct current. Is there a type 2 connector for the second picture? This means that you are recharging with AC current.

Let’s take two examples. We charge Nissan Leaf with 40 kWh battery, AC charging 7.4 kW max, DC charging 46 kW max.

We installed a wall box in the garage and our meter runs a maximum power of 4 kW. Well, the formula is as follows:

Charging time (hours) = Battery capacity (kWh) / Charging power (kW)

For our leaf: 40 kWh / 4 kW = 10 hours (ten hours) to recharge it to 100%. Two things need to be specified: the first is that it won’t take exactly 10 hours, it will take a little longer because there are leaks when you recharge the car, just like when you recharge a computer or smartphone. The second is that it will be very difficult if we need to recharge it from a full discharge: perhaps we will recharge starting from 10% or 25% remaining capacity and so on.

The same formula applies to direct current charging, only the charging power is higher. By recharging our Leaf with a 40kW fast pole, for example, it will take an hour to recharge.

However, unfortunately, in direct current, the above calculation is not the most correct because the batteries do not continuously absorb the maximum power of the shaft. For example, direct current recharging can start at 50 kW, but as the battery recharges the maximum power supplied will drop, and then drop significantly to about 80%.

For this reason, when taking long trips, it is advisable to recharge up to about 80% or, if your car provides it, not to do the calculations and rely on the advice of the on-board computer that will tell you how long you should take. Recharge to reduce total trip time.

Homework: We did the example with the Leaf, try calculating charging times for a Tesla Model 3 in the comments, here are the data for the problem:

– Tesla Model 3 battery: 75 kWh.

– AC Charger Model 3: 11 kW

– Where can I top up? With 11 kW utility pole and in the house with 6 kW wall box and meter.

Write the answer to both questions in the comments: How long does it take to charge the battery from 0 to 100% in the General column? And at home with the 6kW charging box?

How to charge your electric car at home

The ideal situation is to have a garage that is connected to your electric meter (or to a separate meter), or an outlet close to where you park your car, such as a park, driveway or an accessible outside outlet.

When you purchase the vehicle, you will typically receive two cables. The first is Type 2 cable, which is needed to connect to common poles. The second is a cable with a type 2 connector (to be inserted into the car) and terminated at the other end with an Italian 3-pole plug or with a Shuko plug. For a small cost we can change the Italian socket of our home with a Schuko socket (if you don’t already have one) and you have more security. At this point we plug in our slow charger and recharge at a maximum of 2.3 kW.

However, the ideal option is to buy a wallbox which is often offered for free or for a fee by the dealers themselves. Install it and you will have maximum safety, because the wall boxes already have all the protections and the cable is larger, so there is no risk of overheating the socket, even if the latest chargers with Schuko or Italian sockets already have a temperature sensor: just in case As things get hotter, they stop drawing current at maximum intensity and try to lower it. If this is not enough, they are disabled to avoid any security risks.

The charging box will be fixed and will contain the cable with the type 2 connector: at this point follow the previous rule: plug the charging car in when not in use and forget about calculations and strategies, as long as your movements are compatible with the autonomy of the vehicle.

How to charge an electric car in public poles

Nowadays, when you buy an electric car, almost all manufacturers will offer you a card and a subscription account (free for a certain number of years) that allows you to recharge at any public pole, either AC or DC. This is the simplest solution because, while traveling, you just need to follow the car’s navigator, which usually indicates where and how long to charge, stop and use the card to recharge. During small day trips, on the other hand, if you see a charging station nearby or if you search for it via the app, you can take advantage of recharging while shopping, while at the gym, at work, at the doctor’s office, and so on.

Alternatively, there are providers like Enel X (the app is called Juice Pass) and BeCharge that give you an add-on subscription just like the one car manufacturers offer. You register, download the application, order the card if required (not mandatory), fill the vehicle and receive invoices from time to time for automatic payment to your account or credit card. In general, it is recommended to make a subscription to spend less, but we will talk about this in a later episode. Some cities and some shops (restaurants, hotels, supermarkets) offer free top-ups for a specified period of time.

When does an electric car become a burden?

An electric car can become a tedious chore if you don’t have a socket in the garage, although I personally know more than one person who can’t recharge at home and yet has lived with a battery-powered car for quite some time, because they have a public charging station near the apartment. Anyway, the only inconvenience is remembering to recharge the electric car once or twice a week from the nearest pole, then come back to unplug it and park it somewhere else. Over the years, Italy has grown a lot in terms of the availability of charging points, and it is expected that in the not too distant future, every commercial establishment or car park will integrate a large number of poles, with the proliferation of electric vehicles. Today there are already many poles, even if it is true that there are “super” serviced areas and areas where it is difficult to find a recharge point; Also consider this before buying an electric car if you do not have the possibility to charge it at home.