It can be very confusing when you first buy an EV. Here is a brief guide to how it all works.
EV’s have a battery size rather than fuel tank, for example the standard I-Pace model is 90kWh.
This means it needs 90kWh or units of electricity, to get a full charge (200 mile range) so that’s your starting point.
So how do we get 90kWh into the battery?
We use a charger.
EV’s can be charged using a number of different charger sizes.
The most primitive, and this tends to be supplied with the vehicle is a simple 13amp plug socket.
This is the same as any appliance in your house and is plugged into a normal socket. This has a two major problems though, firstly it relies on the house earth arrangements which can be substandard
Most houses now have a new consumer unit with an RCD and this will stop any issues occurring, although it may trip the house out. However in older houses that aren’t equipped with RCD’s and have poor earth arrangements it would not be advisable to use the is method of charging.
If your house does have the old style fuseboard then it would be sensible to get an electrician to check the house over before plugging in.
The other problem with just plugging into a standard socket is that it will only charge at 3kW, using the I-Pace again as the example, this means you could be looking at up to as long as 30 hours to charge the car fully.
This really doesn’t help range anxiety!
7kW fast AC chargers
The most common situation for a domestic house is to install a 7kW charger which either comes with its own RCD and earth arrangement in the form of an external earth rod. Alternatively the existing house arrangement can be used but the installer will check to ensure its up to current regulations.
This typically chargers the I-Pace in around 12 hours, so you can plug it in overnight and be fully charged by the morning. Which for most EV owners is more than sufficient.
22kW & 43kW AC chargers
These require a 3 phase connection which is predominately found in commercial buildings or very large houses. If you are lucky enough to have a 3 phase connection then you can install either one of these and if the car can accept it, it can charge the car in 4 hours and 2 hours respectively.
However, in order for this to happen the car must have an equivalent sized on-board charger. The I-pace for example only has a 7 kW on-board charger as standard so no matter how big your AC charger the car cannot accept more than 7kW.
The on-board chargers are used to change the AC electric that the house supplies into DC electric that the car battery requires.
DC rapid chargers (50-350kW)
Batteries contain DC electricity so this is the best way to charge
By far the quickest way to charge. The majority of current rapid DC chargers are typically 150kW. This means you can get a 75% charge in under 30 minutes, although only a very small number exist. The 350kW DC charger can fully charge an EV in around 10 minutes. These will be the future but at the moment the electricity infrastructure doesn’t exist, so getting permission from the Distribution Network Operator (DNO) is very difficult. Until this changes we wont see too many of this size being installed.
Tesla have their own DC superchargers that can charge at up to 150kW , but for use onlg with Tesla.
Their home chargers can charge up to 22kw but as with any other charger this would you require a 3 phase connection. It is also dependent upon the on-board charger which ranges from 11kW – 22kW depending on the model.
Tesla can also use any charger with a type 2 connection.