Understanding Electric Vehicle Amperage and EV Charger Amperage

Level 3 EV Charging

Lastly, Dc Fast Charging Stations, or Level 3 EV chargers, deliver the highest amperage as well as the fastest charging times—often fully recharging an EV in about an hour.

These commercial-grade chargers, which are not available for residential use and generally cannot be used by PHEVs, can deliver anywhere from 100 to 500 amps, depending on the make and model of the vehicle.

This is the most expensive form of EV charging and is best for when you are driving longer distances, such as a road trip.

One key difference between DCFC and Level 1 and Level 2 EV charging is that DC Fast Charging stations already provide electricity as a DC current instead of an AC current. This is more efficient as the EV will not need to convert the electricity to a DC current to store within the onboard battery.

Matching Your Charger to Your EV

So what happens if your EV charging station and EV have different amperage capacities?

You might wonder if this means you are only able to charge your EV with a charger that has the same amperage and fortunately, this is not the case.

Even if the amperage of your EV charging station and EV are different, your EV will still charge, but you may run into some limitations.

If Your EV’s Amperage Is Higher…

If your EV has a higher amperage rating than the charger you’re using, the charger capacity will limit the flow rate of the current that can reach your EV.

This type of charging mismatch results in a charging speed that is slower than your EV’s capabilities, which can be inconvenient and doesn’t help you get the most out of your EV.

Keep in mind your daily driving needs and mileage will impact the actual amperage needed as well.

If you’re driving significantly less than your vehicle’s range each day or only use your vehicle occasionally, you may not need a charger with the maximum output that your vehicle can accept and it may be more affordable to install a home charger with a lower amperage than your vehicle’s maximum capacity.

If Your EV Charger Amperage Is Higher…

Even if you plug your EV into a charger with a higher amperage, your EV’s onboard charger won’t draw current with a flow rate that is higher than the vehicle’s capacity.

Thanks to your EV and EV charger’s ability to communicate and adjust the current flow rate, there is no risk of damaging your EV when using a high-amperage charger. However, you should know that even though they are rare, malfunctions can happen—especially if any charging components are damaged.

The main issue with using an EV charger with an amperage rating much higher than your vehicle is that you could be overpaying for charging. If you’re considering upgrading your home with a Level 2 EV charger, investing in a high-capacity model could cost more than you would otherwise need to spend, especially if your vehicle isn’t able to utilize the charger’s full power output.

If you’re charging your EV at a public EV charging station, spending more for DC Fast charging might not necessarily be the best option if your vehicle won’t charge faster than its top amperage capacity. Additionally, some public charging locations will offer charging stations with different amperage outputs and you may be able to use a lower output charging station with no impact to the speed of recharging your EV—ensuring the higher-powered EV charging stations are available for other drivers whose vehicles have a higher amperage capacity.

Alternatively, if you have an EV with a relatively low amperage, a public Level 2 EV charging station may also be fully adequate in helping you achieve the fastest possible charging speed and DCFC may be unnecessary, as is the case with most PHEVs and some older BEV models.

Do You Really Need An 80 Amp Charger?

To further put this into perspective using the example above of an 80 amp charger requiring a 100 amp breaker, it is often more expensive to install a high-powered Level 2 EV charging station at home. If your EV is only able to accept a maximum capacity of 48 amps of AC current, installing an 80 amp at-home EV charger is unnecessary and you would be better served by installing a 48 amp charger that only requires 60 amps of breaker capacity.

However, if you are looking at future-proofing your charger in anticipation of any future EVs, you may still want to install a more powerful EV charger, but remember that it will not mean a faster charger for your current vehicle.