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What is EV Charger? How Does EV Charging Work?

Steve

July 9, 2024

4 comments

EV Charger is a device which transfers electric power from the power source to your Electric Vehicle battery. It is technically called Electric Vehicle Supply Equipment (EVSE).

Charging an electric vehicle is a simple process, just like charging your phone.

EVSE (Electric Vehicle Supply Equipment) consists of multiple components. It includes an external charging unit (actually that’s the device people call EV charger or EV charging station), charging cable & connector, charging adapter (if needed), vehicle onboard charger or internal charger and Vehicle’s Battery Management System (BMS).

Both EV charger and Electric Vehicles runs on software which remains the key in all electronic communications while charging, it is also called firmware. The software/firmware also includes a User Control mechanism.

So these were the components of EV charging system.

Now, let’s see how EV charging works looking at the function of each component of the system.

EV Charging Working Mechanism

External Charger or EV Charger:

An external charger often called EV charger or charging station. It is a device which draws the power supply and curates it with appropriate voltage and current to supply power output to EV.

There are many brands making EV charging stations in market currently. Now let’s go to next component in the charging system.

EV Charging Cable:

The power supply is transferred to your EV with a charging cable.

The charging cable remains a link connecting the EV charger and Electric Vehicle.

At one end the charging cable is connected to external EV charger or charging station – from where it receives the power – and at another end it is connected to Electric Vehicle through a charging connector.

Now let’s see the function of charging connector.

EV Charging Connector:

The charging connector is at one end of the charging cable which is also called the charging plug.

Charging connector is to be connected to EV’s charge port in order to charge an EV.

Electric Vehicles have a charging port where the connector which is at one end of cable has to be plugged in to start charging, just like how you plug in cable to your phone for charging.

Now, the charging connector and charge port has to be of perfect male-female fit.

So yes, there are various types of connectors currently used in market.

It includes J1772 type1 and type2, CCS type 1 and CCS type 2, CHAdeMo, ChaoJi, GB/T and NACS.

Here is the detailed article showcasing the features and images of all these connectors.

Not every Electric Vehicle comes with a standard charging port. The majority of the EVs come with J1772 Type 1, J1772 Type 2, CCS1 (type 1), CCS2 (type 2), and NACS port currently. However, the standard is shifting towards NACS in the USA and other countries.

Now if the same type of charge port is not available as of charging connector type then you will need an adapter. So let’s look at its function in the system.

EV Charging Adapter:

A charging adapter is a device which acts as a converter to charge with one type of connector to another type. The adapter fits upon the charging connector which is at one end of charging cable.

Then another end of adapter is to be plugged in to matching charge port of EV.

e.g. If the charger has a J1772 connector and you have NACS port in your EV. Then with J1772 to NACS adapter you can charge your EV.

So J1772 to NACS adapter fits upon J1772 charging connector over cable converting it to NACS and then NACS end of adapter is to be plugged in to your EV.

Internal Charger or Onboard Charger:

Now once you plug the connector to the charge port of your EV the power starts to flow to the EV’s battery.

EV battery always stores electricity in DC form so EVs have an onboard charger built within the vehicle – a part of vehicle’s BMS – which accepts the necessary power supply in AC (Alternate Current) form and converts it to DC (Direct Current) to charge the battery.

This is the case with Level 1 and Level 2 chargers which are AC chargers. Means it gives power output in AC form to charge the battery in an EV. If you don’t know about different types of EV charging stations then here you go. Thre’s a separate article covering all various types of EV chargers.

Now, if charging with direct DC power in case of Level 3 charger or DC charger then the onboard charger will be bypassed. Because there is no need to convert it to DC, as power is already in DC form. So it directly charges the battery. This makes EV charging very fast. So these chargers are also called fast chargers.

Now there’s one component in EV charging system in Electric Vehicle which maintains the charging process in a proper way as needed. Let’s look at that now.

Battery Management System (BMS):

Battery Management System is part of Electric Vehicle and it curates incoming power and controls the whole vehicle’s internal charging system with protection and safety measures.

It takes care of EV’s battery in such a way that the least battery degradation happens by controlling the supply of power to the battery.

This onboard charger which is part of vehicle Battery Management System (BMS) forms the vehicle’s internal charging system.

Firmware & User Control Interface:

And there is software or firmware which is a set program for the electronic components in the EV charger and Electric Vehicle to conduct the charging process in a certain manner.

It facilitates all electronic communications between EV charger and vehicle to conduct the charging process as needed.

It communicates with Vehicles’s onboard charger, BMS to calculate how much power is needed and the same is communicated with external EV charging station and making sure the needed power is being supplied to EV’s battery.

Any changes of power during charging process will be communicated effectively by this software, considering the need of power and safety of Electric Vehicle, EV’s battery and EV charger.

This firmware is installed separately in EV charger and Electric Vehicle. EV charger and vehicle actually come with installed software by the manufacturer when you buy and have separate functions to facilitate the charging process.

You also receive over the air firmware updates in order to enhance the features of software and remove any existing glitches.

It also includes a user control mechanism like a dashboard screen and phone app for the car & phone app for the EV charger.

Electric Vehicle’s app is used to facilitate initial set up and has charging related settings apart from all other EV’s functional controls.

EV charger’s app is also used to facilitate the initial setup, but mostly it is used to control the charging process solely. Unless EV charger brand has ecosystem of devices then they may have all in one app to control all other devices.

If EV charger supports the app integration then it also provides smart charging functions like, schedule charging, off-peak charging, charging stats reporting, access controls, etc There are many smart charging functions like this.

Your EV and EV charger also receive over-the-air firmware updates to enhance the control features or to remove any technical glitch.

However, not all EV chargers or EVs provide a full user interface. It may be totally absent or come with varied range of options. But mostly all EVs & EV chargers come with a user interface.

So this was all about how EV charging works with detail into each component of EV charging system.

In a Nutshell

So when you undock and lift the charging cable from (external!) EV charger orEV charging station and plug in to your Electric Vehicle’s charge port, the power flows from EV charger to your EV’s battery and you see.. ohh EV is charging! And It will be ready to shoot on the road once charged.

Conclusion

So Charged-up drivers OR Future EV owners, I hope now you have sufficient understanding of how EV Charging works.

Let me know in the comments if you have any doubts.

OK then see you in the next article!