What is an onboard charger for an EV or PHEV?

Technically a Level 1 or Level 2 EV charger is really an EVSE, or Electric Vehicle Supply Equipment. This feeds electricity to an onboard charger in the EV or PHEV, and that onboard charger converts electricity from AC to DC and charges the battery. Some PHEVs can only accept 16 amp chargers and 3 to 4 kW from Level 2 chargers. This is much slower than the 11.5+ kW most EVs can accept.

Onboard chargers come in many shapes and sizes, and they ultimately impact how fast a car can be charged from home. Let’s look at a few examples of onboard charger speeds, noting that generally more kW = faster charging and better charging experience:

• Toyota Rav4 Prime SE 2022 PHEV: 3.3 kW onboard charger
• Volvo XC90 Recharge PHEV 2024: 3.7 kW onboard charger
• Jeep Wrangler 4xe PHEV 2023: 7.2 kW onboard charger
• Nissan Ariya Premier 2023: 7.2 kW onboard charger
• Audi e-tron Premium Plus 2023: 9.6 kW onboard charger
• Mercedes Benz EQS 2023: 9.6 kW onboard charger
• Tesla Model X Performance 2023: 11.5 kW onboard charger
• Rivian R1T: 11.5 kW onboard charger
• Lucid Air Touring 2023: 19.2 kW onboard charger

The difference between a 3.3 kW onboard charger and a 19.2 kW onboard charger is MASSIVE. With a typical efficiency of an EV around 3.5 miles / kWh, this could be the difference in adding 11 miles of range in one hour (3.3 kW) or 67.2 miles of range in one hour (19.2 kW). That is 6x faster charging, and both are Level 2 chargers!

What is the typical onboard charger size for a PHEV?

The typical PHEV has an onboard charger of 7.2 kW. The Jeep Grand Cherokee 4xe and Jeep Wrangler 4xe models all have 7.2 kW onboard chargers, which mean that a Level 2 charger could feed 32 amps at 240 volts to this car, and the PHEV will accept the charge.

PHEV models that only accept 3 kW through their onboard chargers are where charging takes much longer that it should.

What is the formula for calculating kilowatts using volts and amps?

P (kW) = I(A) × V(V)/1,000

So, if you have a 48A Level 2 charger and a 240V line, this leads to: 48 x 240 = 11,520 / 1,000 = 11.5 kW.

Compare this to a 16A Level 2 charger and a 240V line, this leads to: 16 x 240 = 3,840 / 1,000 = 3.8 kW.

Where can I learn more?

We have information on range, battery sizes, charging speeds, and more on our EV Listings Pages. Make sure you know the size of your onboard charger before purchasing an EV or PHEV. A larger onboard charger will lead to a better quality of life, faster home charging, and an overall positive experience in your transition to an electric lifestyle.