About 7kw EV charger
Since the charging rate of electric vehicles is in kilowatts, a 7kw electric car charger refers to a charger with a maximum output power of 7 kilowatts. It is currently the most commonly used electric car charging station, which can quickly provide energy for home cars. Because of its low output power, we only need to install a single-phase power supply① to use it.
① Single-phase power supply: It consists of a live wire and a neutral wire, which can provide stable power output for places with low power demand such as homes or offices, and can provide electric vehicles with a maximum power output of 7.4 kilowatts.
About 22kw EV charger
From the output power, we can see that the power output capacity of 22kw electric vehicle charger is three times faster than that of 7kW electric vehicle charger, so the charging time will be greatly shortened by 22kw electric vehicle charger. It uses three-phase power supply② to provide energy output, and is the electric vehicle charger with the highest output power that can be installed at home.
②Three-phase power supply: The composition of three-phase power supply is more complicated, mainly composed of three independent alternating currents, so it can output more power at one time. Since three sets of alternating currents act at the same time, the voltage and current are more stable, and it is mainly used in industrial production or transportation.
7kW VS 22kW EV charger: power supply selection
From our experience, if the charging speed of 22kw electric vehicle charger is three times that of 7kw electric vehicle charger, then shouldn’t I just buy 22kw electric charger? However, in fact, it is not the case.
When we choose a power supply, we first need to consider whether our power supply is single-phase or three-phase. If it is a single-phase power supply, directly using a 22kw electric vehicle charger may cause line overheating or circuit tripping.
Secondly, we also need to consider whether our car supports 22kw charging. There are not many cars on the market that support 22kw charging. The most common ones are Tesla, Maserati, BMW, BYD and Audi, and you also need to pay attention to their models, because only a few of these models support 22kw. If you accidentally buy an electric car that only supports 7kw, then even if you install a 22kw charger, it will either not work or can only charge at 7kw.
Basic requirements for 22kw power selection
- The car supports 22kw power charging
- A three-phase power distribution box is installed
- Use copper wires of not less than 10 square millimeters
- The heat dissipation of the distribution box is good and the voltage connected is stable
7kw vs 22kw EV charger compatibility
In addition to supporting 22kw fast charging, all 22kw electric car chargers also support 7kw slow charging, which means that if the electric car supports it, it can output 7kw or 22kw according to the type of plug, so 22kw electric cars are more compatible. But the reverse is not true.
7kw vs 22kw EV charger: cost
Since the performance and usage requirements of 22kw electric vehicle chargers are higher, the cost is 2-3 times that of 7kw, and the labor cost of $300-700 is required for installation, so the overall cost will be high.
However, some places have certain subsidies for electric vehicle chargers. For example, the UK limits the upper limit of each installation fee to $460, and can get up to 75% subsidy if it meets the government's Electric Vehicle Home Charging Scheme (EVHS).
7kw vs 22kw EV charger: how to choose?
For most families, it is not cost-effective to use a 22kw EV charger because it needs to meet too many conditions. Secondly, most families charge at night and use it during the day. Therefore, the basic 7kw EV charger is sufficient for daily use.
However, commercial centers and office spaces are more suitable for 22kw electric chargers. First, most of the vehicles that can be charged in these places are in urgent need of charging because they have no power. Secondly, because of the parking fee, the faster the charging, the less parking fee is spent. If the charging rate is changed to 7kw, the parking fee alone will be three times more expensive, which is very uneconomical.
In addition, judging from the planning of electric vehicles in many countries, more and more high-power electric vehicles will appear in the future, so planning in advance can catch up with the best time.
