Frequently Asked Questions:
Backup Battery Charger Systems

The California Energy Commission adopted battery charger system regulations on January 12, 2012. The regulations include efficiency standards for backup battery charger systems. Compliance for battery charger systems sold or offered for sale in California became mandatory for consumer battery charger systems manufactured on or after January 1, 2013, and for non-consumer battery charger systems manufactured on or after January 1, 2017. Products excluded from the scope of the battery charger system regulations are described in Title 20 California Code of Regulations (CCR) section 1601(w).

The U.S. Department of Energy has efficiency standards and test procedures for consumer battery chargers, but does not cover non-consumer battery chargers or any type of backup battery charger systems. As a result, the Energy Commission is not preempted from having its own standards or test procedures for backup battery charger systems and non-consumer battery charger systems.

General

What types of products incorporate backup battery charger systems?

Products incorporating backup battery charger systems are typically either:

  1. Products whose primary function is to provide backup power only during a power failure. This type of product is “off” when regular power is available. An example is an emergency driver pack for linear LED lighting.
  2. Products whose primary function is to operate under all conditions, regardless of the power source. This type of product is often “on” continuously. An example is an alarm system that provides continuous functions, such as monitoring, sensing, and communications and that also has a battery backup so those functions are still performed during a power failure.

Definitions

Where are the definitions related to state-regulated battery charger systems located in the regulations?

The definitions related to state-regulated battery charger systems are located in Title 20 CCR section 1602(w), as are the definitions related to federally regulated battery chargers.

What is the definition of a state-regulated battery charger system?

See the definition in Title 20 CCR section 1602(w). Basically, the term means a battery charger coupled with its batteries or battery chargers coupled with their batteries. It covers all rechargeable batteries or devices incorporating a rechargeable battery and the chargers used with them. It does not include federally regulated battery chargers that are covered under standards in Title 10 Code of Federal Regulations (CFR) section 430.32(z).

What is the definition of a backup battery charger system?

See the definition in section 1602(w). In summary, the term means a small battery charger system that is voltage and frequency dependent and designed to provide power to an end use product in the event of a power outage. All backup battery charger systems, regardless of rated input power, are defined as small battery charger systems and are required to use the same test procedure.

What is the definition of battery maintenance mode (maintenance mode)?

See the definition in section 1602(w). Battery maintenance mode (maintenance mode) means the mode of operation when the battery charger system is connected to the main electricity supply and the battery is fully charged, but is still connected to the charger.

Efficiency Standard

What efficiency standard applies to a backup battery charger system?

The applicable efficiency standard is found in Title 20 CCR section 1605.3(w)(4). It requires that backup battery charger systems consume no more than 0.8 + 0.0021 x Eb watts in maintenance mode, where Eb is the battery capacity in watt-hours.

Why don’t backup battery charger systems have an efficiency standard for active charge mode?

Because backup battery charger systems discharge energy only during power outages, the battery remains fully charged most of the time. The primary purpose of the battery charger system in a product with a battery backup is to maintain the battery’s charge. It is only infrequently engaged in actively charging a depleted battery, typically after a power outage. Therefore, only the energy consumption during maintenance mode has an efficiency standard as this is where the bulk of the energy savings are likely to be found.

Test Procedure

What is the test procedure for backup battery charger systems?

The test procedure requirement is found in Title 20 CCR section 1604(w), which incorporates Title 10 CFR section 430.23(aa) (Appendix Y to subpart B of part 430) (January 1, 2016) as the test procedure. A copy of the test procedure can be found at https://www.govinfo.gov/content/pkg/CFR-2016-title10-vol3/pdf/CFR-2016-title10-vol3-part430-subpartB-appY.pdf.

Does the test procedure apply to backup battery charger systems which operate at other than DC or 115 volts AC?

Yes. The adopted test procedure (see previous question) applies to all covered backup battery charger systems, regardless of their operating voltage. Because it is a state-regulated product, any federal scope restrictions to the test procedure are not applicable.

How do you test backup battery charger systems that are embedded in products with non-battery-charger functions?

The test procedure allows for disabling of any optional functions controlled by the user and not associated with the battery charging process. Cables and connectors not required for battery charging, but associated with other functionality, may be left disconnected during testing.

How do you test backup battery charger systems with non-battery-charger functions that are not controlled by the user?

Many products with a battery backup are explicitly designed to prevent the primary function from being disabled (e.g., fire alarm system). When the test procedure is followed, the measured energy consumption for the backup battery charger system includes both battery maintenance mode energy and the energy used for the primary (non-battery-charger) functions.

For products where the non-battery-charger functions cannot be disabled, but are normally off or are very small loads, the test procedure can likely be used successfully.

For products where the non-battery-charger functions cannot be disabled, but are normally on, the test procedure does not specify how to disaggregate the energy consumption of the backup battery charger system from the energy consumption of the non-battery-charger-related functions. In these cases, the maintenance mode electricity consumption of the battery charger is likely to be indistinguishable from the electricity consumption of the overall product. Product design approaches may alleviate these challenges. For example, products designed with a switch to isolate the backup battery charger system for testing purposes, even if it is accessible only to the test technician, would allow the test laboratory to isolate the battery charger function and determine its energy consumption, and is therefore consistent with the test procedure. As another example, a test laboratory can arithmetically determine the energy consumption of a backup battery charger system in products designed to facilitate measurement of energy consumption in more than one operating mode (e.g., with a fully charged battery, with no battery), again consistent with the test procedure.

What if a product does not incorporate the design approaches discussed in the examples provided in response to the previous question?

Manufacturers of backup battery charger systems for which the maintenance mode energy consumption of the backup battery charger system can be measured or determined, in a manner consistent with the test procedure, should continue certifying their products to the Energy Commission as required by the regulations.

For some products, it may not be possible to determine the energy consumption of only the backup battery charger system. See the Regulatory Advisory posted on the Energy Commission’s website.