Battery Chargers and External Power Supplies
The Department of Energy (DOE) does not currently regulate battery chargers. Energy conservation standards have been in place for external power supplies since 2007. Battery chargers charge batteries for consumer products, including battery chargers embedded in other consumer products. Examples of this product include chargers for cell phone or computer batteries. External power supplies convert household electric current into direct current or lower-voltage alternating current to operate a consumer product such as a computer or computer monitor. Currently only Class A external power supplies are covered by standards.
The current standard will save approximately 3.8 quads of energy and result in approximately $42.4 billion in energy bill savings for products shipped from 2008-2032. The standard will avoid about 198.5 million metric tons of carbon dioxide emissions, equivalent to the annual greenhouse gas emissions of about 39 million automobiles.
The Standards and Test Procedures for this product are related to Rulemaking for Battery Chargers and External Power Supplies Energy Conservation Standard.
Recent Updates | Standards | Test Procedures | Waiver, Exception, and Exemption Information | Statutory Authority | Historical Information | Contact Information
DOE has published a notice of proposed rulemaking regarding energy conservation standards for battery chargers and external power supplies. 77 FR 18478 (March 27, 2012). This proposal would establish energy conservation standards for battery chargers and non-Class A external power supplies. It also proposes to amend the standards that are currently in place for Class A External Power Supplies and to establish new labeling requirements for battery chargers and EPSs.
DOE published a request for information regarding energy conservation standards for battery chargers and external power supplies. 78 FR 18253 (March 26, 2013). The comment deadline is May 28, 2013. For more information, please see the rulemaking page.
Standards for Battery Chargers and External Power Supplies
The following content summarizes the energy conservation standards for Class A external power supplies. The text is not an official reproduction of the Code of Federal Regulations and should not be used for legal research or citation.
There are currently only energy conservation standards for Class A external power supplies. There are no energy conservation standards in place for non-Class A external power supplies nor for battery chargers. Class A external power supplies manufactured and distributed in commerce, as defined by 42 U.S.C. 6291 (16), on or after July 1, 2008 must meet the energy conservation standards specified in the Code of Federal Regulations, 10 CFR 430.32(w). This information is also available in the Electronic Code of Federal Regulations.
The term "class A external power supply" means a device that—
- is designed to convert line voltage AC input into lower voltage AC or DC output;
- is able to convert to only 1 AC or DC output voltage at a time;
- is sold with, or intended to be used with, a separate end-use product that constitutes the primary load;
- is contained in a separate physical enclosure from the end-use product;
- is connected to the end-use product via a removable or hard-wired male/female electrical connection, cable, cord, or other wiring; and
- has nameplate output power that is less than or equal to 250 watts.
The term "class A external power supply" does not include any device that—
- requires Federal Food and Drug Administration listing and approval as a medical device in accordance with section 360c of title 21; or
- powers the charger of a detachable battery pack or charges the battery of a product that is fully or primarily motor operated.
Table 1. Energy Conservation Standards for Class A External Power Supplies
||Minimum Efficiency (decimal equivalent of a percentage)
||0.5 times the nameplate output
|1 to not more than 51 Watts
||The sum of 0.09 times the natural logarithm of the nameplate output and 0.5
|Not more than 250 Watts
For further guidance or to submit questions related to the implementation of this standard, visit the Guidance and Frequently Asked Questions page.
Current Test Procedure
To determine compliance with DOE standards, manufacturers must follow the test procedures specified at 10 CFR 430.23(aa) for battery chargers and external power supplies 10 CFR 430.23(bb). The methods to conduct the test procedure for battery chargers are further specified in 10 CFR Part 430 Appendix Y to Subpart B, and the methods to conduct the test procedure for external power supplies are further specified in 10 CFR Part 430 Appendix Z to Subpart B. These are also in the Electronic Code of Federal Regulations.
For further guidance or to submit questions related to the implementation of this test procedure, visit the Guidance and Frequently Asked Questions page.
Test procedure waivers have not been issued for battery chargers or for external power supplies.
For information about obtaining test procedure waivers, see 10 CFR section 430.27.
DOE's Office of Hearings and Appeals has not authorized exception relief for battery chargers nor for external power supplies.
For information about obtaining exception relief, see 10 CFR part 1003.
State Exemptions to Federal Pre-emption
DOE has not exempted any state from this energy conservation standard. States may petition DOE to exempt a state regulation from preemption by the Federal energy conservation standard. States may also petition DOE to withdraw such exemptions. For details, see 10 CFR part 430, subpart D.
Small Business Exemptions
Any manufacturer of a covered product with annual gross revenues that do not exceed $8,000,000 from all its operations and meets certain other conditions may apply for an exemption to the energy conservation standard. For details, see 10 CFR part 430, subpart E.
Congressionally Mandated Exemptions
Certain external power supplies used in security and life safety alarms and surveillance systems are exempt from the no-load mode power requirements that apply generally to Class A external power supplies. This exemption took effect on October 19, 2011. For details, see 76 FR 57897 (September 19, 2011).
The Energy Policy and Conservation Act (EPCA) also provides an exemption from standards for any Class A external power supply manufactured between July 1, 2008 and June 30, 2015 that is made available as a service part or a spare part (replacement part) for an end-use product manufactured before July 1, 2008 is excepted from the energy conservation standards. For details, see 76 FR 57897; 57899-57900.
The current energy conservation standards for battery chargers and external power supplies are mandated by Part A, the ‘‘Energy Conservation Program for Consumer Products Other Than Automobiles’’ of Title III of the Energy Policy and Conservation Act (EPCA), as amended. (42 U.S.C. § 6291–6309) These appliances are treated as covered products’ under Part A. (42 U.S.C. 6295(u))
The Energy Policy Act of 2005 (EPACT 2005) and the Energy Independence and Security Act of 2007 (EISA 2007) amended EPCA with regard to the energy conservation program for battery chargers and external power supplies.
EPCA, as amended by EPACT 2005 and EISA 2007, sets efficiency standards for Class A external power supplies and mandates various rulemaking activities. (42 U.S.C. 6295(u)(3))
The statute also requires DOE to issue a final rule prescribing energy conservation standards for battery chargers (42 U.S.C. 6295(u)(1)(E)(i)(II) as well as perform a determination analysis for external power supplies excluded from the July 1, 2008, standard. (42 U.S.C. 6295(u)(1)(E)(i)(I) These rulemakings will be bundled with the rulemaking for Class A electronic power supplies, as the products are closely related.
Previous Test Procedures
2009 Final Rule
2006 Final Rule
Helpful Links and Contact Information
Find tips and guidance for making your home, workplace, or vehicle more energy efficient visit EnergySavers.gov.
DOE supports the testing and verification of ENERGY STAR® products in close collaboration with the Environmental Protection Agency. ENERGY STAR qualified battery chargers are on average 35 percent more energy efficient than standard models.
For more information related to the regulation of this product, please email: