Since about 10 years ago, when the first DC fast chargers were shown/installed, they were often called Level 3, both by EV enthusiasts and manufacturers. Formally, it's wrong.

A very informative video by Professor John D. Kelly from the Weber State University (WSU), explains the SAE J1772 charging standard (from 2016), including previous versions/propositions of the standard, as well as the types of charging points (AC charging terminal and DC chargers).

Formally, the power level of up to 400 kW is still Level 2 (in opposition to considering a 50 kW DC charger a Level 3):

  • AC Level 1: up to 1.92 kW
  • AC Level 2: up to 19.2 kW (80 A at 240 V)
  • DC Level 1: up to 48 kW
  • DC Level 2: up to 400 kW (400 A at 1,000 V)

* maybe there will be a Level 3 at some point in the future when the power output goes beyond 400 kW (for trucks/buses for example).

** There are also other charging standards like the CHAdeMO (commonly 50 kW was from the beginning also called a Level 3) or Tesla proprietary standard.

At 10:19 in the video, we can see a detailed description of all charging contacts of the SAE J1772 DC Level 2 inlet (also called CCS/Combined Charging Standard Type 1 as there is a different CCS2/Type 2 version for Europe and most of the rest of the world).


We are very thankful to Professor John D. Kelly for this and many other videos as they bring us invaluable educational value.

Video Description via WeberAuto on YouTube:

There is no such thing as a Level 3 EV charger

Forget what you have heard, there is no such thing as a Level 3 EV charger. Join me to learn about the four actual EV and PHEV charging methods of the SAE J1772 Surface Vehicle Standard.

Video Timeline:

Video introduction at 0:12

4 Charging Methods of J1772 at 0:28

J1772 history at 0:40

1996 and 2001 Level 3 charging proposals at 0:48

J1772 is for conductive charging at 1:10

J1773 Inductive charging at 1:19

erminology and electrical principles at 1:35

1. All EVs and PHEVs use two different DC batteries at 1:45

2. DC Batteries need to be charged with DC power at 2:22

3. The 12V battery is charged with power from the high voltage DC battery at 2:29

Most off-board chargers supply AC power to the vehicle 2:34

4. AC power is converted to DC power by the on-board charging module (OBCM) at 2:56

2018 Tesla Model S P100D OBCM at 3:45

2018 Chevrolet Volt OBCM at 3:53

2017 Chevrolet Bolt EV OBCM at 3:53

There are two different J1772 AC charging levels at 5:18

There are two different J1772 DC charging levels at 6:20

DC Level 1 charging and Tesla charging at 6:58

5. Charge rate control at 7:42 (*See correction below)

Level 2 Charge Coupler (CCS) at 9:20

AC and DC charging contacts at 10:18

Contact 1 AC L1 and DC+ at 10:56

Contact 2 AC N, L2, and DC- at 11:19

Contact 3 Protective Earth (PE) at 11:45

Contact 4 at Control Pilot (CP) 11:50 (*See correction below)

Contact 5 Control Status (CS) at 12:30 (*See correction below)

and contact 5 at Proximity Detection (PD) at 13:27

Contact 6 DC+ at 14:15

Contact 7 DC- at 14:39

J1772 recommended practice verses surface vehicle standard at 14:43

Electric Vehicle Supply Equipment (EVSE) standards at 15:58

NFPA Document 70 NEC Article 625 at 16:18

J1772 off-board charger to vehicle EVSE standards at 17:32

Off-board chargers need to be (UL) listed, Intertek (ETL) Listed, CSA certified, or ANSI certified to verify EVSE compliance at 17:58

Video wrap-up at 18:45
Download my pdf of the J1772 Level Charge Receptacle here:

*CORRECTIONS: I made some mistakes in the video and thanks to the great feedback I have received, the following corrections need to be made.

1. When using an EVSE compliant AC charging station or cord set, this equipment (EVSE) is not technically considered a charger. Instead, it passes the AC power to the vehicle's on-board charger where it is converted to DC power to charge the vehicle's battery.

2. Control Pilot (CP) Contact #4.

- For AC Level 1 and AC Level 2 charging, the vehicle does not signal the EVSE how much current it needs. Instead, the external equipment (EVSE) signals the vehicle how much current it is capable of providing. Next, the vehicle's on-board charging module takes whatever amount of current it needs up to that limit.

- For DC Level 1 and AC Level 2 charging, the off-board charger signals the vehicle that Power Line Communication (PLC) is necessary. Using PLC over the Control Pilot (CP) circuit, the vehicle's on-board power line communication module tells the off-board DC charger how much current to supply to charge the vehicle's battery.

3. Proximity Detection (PD).

Contact #5 of the J1772 charge coupler (CCS Receptacle) uses Proximity Detection (PD), not Proximity Pilot (PP). Proximity Detection detects the connection to the vehicle (as described in the video). Proximity Pilot (PP) is not used in the USA, it is used in some other countries where the charging coupler cable from the EVSE to the vehicle can be swapped to another cable which may or may not be able to carry the same current. The Proximity Pilot signal indicates how much current the cable can handle.

4. I have updated my graphic of the J1772 DC Level 2 Charge Coupler. You can download it here:

Weber State University (WSU) - Department of Automotive Technology - Ardell Brown Technology Wing - Transmission Lab.
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This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see
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