Certification to UL 2202 - Part II

15 Feb 2013

An EV battery charger is typically AC in/DC out, and provides charging voltage directly to the vehicle battery. These systems are typically used to provide higher power levels and thereby faster charging than the onboard chargers.

U.S. requirements
An EV battery charger is typically AC in/DC out, and provides charging voltage directly to the vehicle battery.  These systems are typically used to provide higher power levels and thereby faster charging than the onboard chargers.  Most onboard chargers will be limited either by heat dissipation or available AC power, such that 3-7kW is the max charging rate, while off-board systems may be rated 50kW or higher maximum charge rates. 

From a certification standpoint in the U.S., both types of EVSE must comply with the National Electric code, Article 625.  Specific safety standards of interest are UL 2594 for Charging Stations and UL 2202 for EV Battery Chargers.  UL 2202 specifically applies to Battery Chargers used to recharge electric vehicle batteries, and has different requirements than those of existing 12V Starter Battery chargers (UL 1236), or industrial batteries, such as forklifts (UL 1564).

UL 2202 combines the "typical" safety requirements for any large DC power supply with the EV-specific Personnel Protection and Connector safety requirements.  The type of Personnel Protection safety device used in a DC charger will differ from those used in an AC charging station.  While AC charge stations often utilize GFI (Ground Fault Interrupt) devices, the DC chargers utilize an Isolation Monitor or similar circuits to monitor any loss of insulation between the charge conductors and ground.

It also is worth noting that on-board chargers are not required to contain this personnel protection circuit, since the off-board charge station, which is connected to grid power and provides power to the onboard charger, is required to contain this safety circuit.

Canadian variations
For products installed in Canada, it is worth noting that UL 2202 is not yet harmonized with Canadian requirements.  Currently, Canadian chargers and charge stations are listed to CSA C22.2 #107.1.  Additionally, Technical Information Letters (TIL) have been issued to ease the certification process in the interim.  Also, Special Inspections (SI), may be utilized, similar to the U.S. field label program.

Do you have a question about the US or Canadian UL requirements for testing EVSE to UL 2202? Please leave your comment below and one of our experts will get back to you.