New CEC Standards for Industrial Battery Chargers
What Do You Need To Know?
By: Nasser Kutkut, PhD
The California Energy Commission (CEC) has enacted new standards for all types of battery chargers that start taking effect in 2013. This includes forklift truck battery chargers (industrial chargers), for which the standards will begin taking effect January 1, 2014.
The new CEC battery charger standards require chargers to be more efficient and waste less energy all throughout the charger operating modes, namely during the charging cycle as well as during standby and off modes. The goal is to reduce energy wasted by battery chargers, which is estimated to save California 2,200 gigawatt-hours each year (enough energy to power nearly 350,000 homes).
Starting January 2014, industrial battery chargers manufactured after that date will have to comply with minimum performance requirements that include:
These new standards will most likely make SCR and ferro-resonant chargers obsolete, pushing manufacturers toward new higher efficiency charging technologies.
Another implication of the new CEC standards is that the new efficiency standards define testing and reporting requirements for specifying charger efficiency. Most charger OEMs report only the maximum efficiency that the charger can achieve. However, the new standards require OEMs to report the overall charge cycle efficiency by taking efficiency measurements at 25%, 50%, 75%, and 100% of full rated power and calculating the arithmetic average of the resulting efficiencies. As such, new chargers must not only be efficient at full power or during the bulk charging mode of the charge cycle, but must also be efficient at lower power levels during the finish and equalize charge modes.
The new requirement will require designers of battery chargers to focus on the total amount of energy consumed in the process of converting AC electricity from the utility grid into DC electricity stored in the battery so as to develop techniques to minimize energy waste throughout the charge cycle.