This blog post discusses the electrical car charging technology.
Level 1, 2, and 3 charging
Around 1998 the California Air Resources Board classified levels of charging power that have been codified in title 13 of the California Code of Regulations, the U.S. 1999 National Electrical Code section 625 and SAE International standards.
|Level||Original definition||Coulomb Technologies’ definition||Connectors|
|Level 1||AC energy to the vehicle’s on-board charger; from the most common U.S. grounded household receptacle, commonly referred to as a 120 volt outlet.||120 V AC; 16 A (= 1.92 kW)||SAE J1772 (16.8 kW), ordinary household 120 volt outlet|
|Level 2||AC energy to the vehicle’s on-board charger;208 – 240 volt, single phase. The maximum current specified is 32 amps (continuous) with a branch circuit breaker rated at 40 amps. Maximum continuous input power is specified as 7.68 kW (= 240V x 32A*).||208-240 V AC; 12 A – 80 A (= 2.5 – 19.2 kW)||SAE J1772 (16.8 kW), IEC 62196 (44 kW), Magne Charge (Obsolete), Avcon, IEC 60309 16 A (3.8 kW) IEC 62198-2 Type2 same as VDE-AR-E 2623-2-2, also known as the Mennekes connector (43.5 kW)IEC 62198-2 Type3 also known as Scame|
|Level 3||DC energy from an off-board charger; there is no minimum energy requirement but the maximum current specified is 400 amps and 240 kW continuous power supplied.||very high voltages (300-600 V DC); very high currents (hundreds of Amperes)||Magne Charge (Obsolete) CHΛdeMO (62.5 kW),|
.* or potentially 208V x 37A, out of the strict specification but within circuit breaker and connector/cable power limits. Alternatively, this voltage would impose a lower power rating of 6.7 kW at 32A.
More recently the term “Level 3″ has also been used by the SAE J1772 Standard Committee for a possible future higher-power AC fast charging standard. To distinguish from Level 3 DC fast charging, this would-be standard is written as “Level 3 AC”. SAE has not yet approved standards for either AC or DC Level 3 charging.
For comparison in Europe the IEC 61851-1 charging modes are used to classify charging equipment. The provisions of IEC 62196 charging modes for conductive charging of electric vehicles include Mode 1 (max. 16A / max. 250V a.c. or 480V three-phase), Mode 2 (max. 32A / max. 250V a.c. or 480V three-phase), Mode 3 (max. 63A (70A U.S.) / max. 690V a.c. or three-phase) and Mode 4 (max. 400A / max. 600V d.c.).
Most electric cars have used conductive coupling to supply electricity for recharging after the California Air Resources Board settled on the SAE J1772-2001 standard as the charging interface for electric vehicles in California in June 2001. In Europe the ACEA has decided to use the Type 2 connector from the range of IEC_62196 plug types for conductive charging of electric vehicles in the European Union as the Type 1 connector (SAE J1772-2009) does not provide for three-phase charging.
Another approach is inductive charging using a non-conducting “paddle” inserted into a slot in the car. Delco Electronics developed the Magne Charge inductive charging system around 1998 for the General Motors EV1 and it was also used for the Chevrolet S-10 EV and Toyota RAV4 EV vehicles.