Sources<\/a><\/li>\n<\/ul>\n<\/nav>\n<\/div>\nDirect answer: what efficiency rules apply to my power supply?<\/h2>\n External power supplies must meet minimum average efficiency and a maximum no-load (standby) power before they can be sold in major markets.<\/strong> In practice, external power supply efficiency is set by two limits: how much energy is wasted while working, and how much is drawn while idle. In the United States that rule is DOE Level VI<\/strong>. In the European Union it is Regulation (EU) 2019\/1782<\/strong> under Ecodesign, with the voluntary Code of Conduct Tier 2<\/strong> as the common industry benchmark. Both push the same way: less energy wasted as heat, lower vampire draw. A GaN-based supply clears them more easily. Paiyi Power designs to these rules and holds CE, CB, FCC and ISO 9001.<\/p>\nFinished goods warehouse at Paiyi Power \u2014 units built to DOE and EU ErP efficiency rules<\/figcaption><\/figure>\nWhy external power supply efficiency standards exist<\/h2>\nStandby and vampire power<\/h3>\n Billions of supplies stay plugged in doing nothing. The no-load draw of each one is small, but multiplied across a market the wasted energy is large. External power supply efficiency rules exist to cap that standby loss and to raise the efficiency of the supply while it is working.<\/p>\n
The cost of wasted watts at scale<\/h3>\n A few lost points of efficiency become real heat and real electricity cost across a product fleet. For a B2B buyer, an efficient supply is also a cooler, longer-lived supply \u2014 the efficiency rule and the reliability goal point the same way.<\/p>\n
The three rules at a glance<\/h2>\n \n\n\nStandard<\/th>\n Region<\/th>\n What it sets<\/th>\n Status<\/th>\n<\/tr>\n<\/thead>\n \n\nDOE Level VI<\/strong><\/td>\nUnited States<\/td>\n Min. average efficiency + max no-load<\/td>\n Mandatory<\/td>\n<\/tr>\n \nEU ErP (Reg. (EU) 2019\/1782)<\/strong><\/td>\nEuropean Union<\/td>\n Ecodesign efficiency + no-load<\/td>\n Mandatory<\/td>\n<\/tr>\n \nCoC Tier 2<\/strong><\/td>\nEU \/ voluntary<\/td>\n Stricter efficiency benchmark<\/td>\n Voluntary<\/td>\n<\/tr>\n \nUSB PD (IEC 62680)<\/strong><\/td>\nGlobal<\/td>\n PD spec for USB-C outputs<\/td>\n Specification<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nDOE Level VI (United States)<\/h2>\nWhat it requires<\/h3>\n DOE Level VI sets a minimum average efficiency measured across load levels (commonly a four-point average at 25%, 50%, 75% and 100% of rated output) and a tight cap on no-load power. Supplies that fail cannot be legally placed on the US market.<\/p>\n
Who it applies to<\/h3>\n It covers external ac-dc and ac-ac power supplies within defined nameplate power bands. If you ship chargers or adapters to the US, your model must meet it \u2014 there is no consumer-versus-B2B exception that lets a non-compliant unit through.<\/p>\n
EU ErP \u2014 Regulation (EU) 2019\/1782<\/h2>\nEcodesign requirements<\/h3>\n The EU Ecodesign regulation for external power supplies sets efficiency and no-load limits similar in spirit to DOE Level VI, and it sits alongside the EU energy-label framework. A supply sold in the EU must comply, and the model appears in the EU product database (EPREL).<\/p>\n
CoC Tier 2 benchmark<\/h3>\n The Code of Conduct Tier 2 is a voluntary but widely referenced stricter benchmark. Many EU buyers ask for “CoC Tier 2” as a quality signal even though it is not legally mandatory. Designing to CoC Tier 2 means you clear the legal ErP floor with margin to spare.<\/p>\n
How external power supply efficiency is measured<\/h2>\n Efficiency is output power divided by input power. Rules use an average<\/strong> across load points, not a single best-case number, so a supply cannot cheat the test by peaking at one load. The no-load figure is measured with the supply plugged in and delivering nothing. A credible supplier reports both, and the report names the exact model.<\/p>\nWhy GaN makes compliance easier<\/h2>\n Because a GaN switch wastes less energy as heat, a GaN supply reaches higher external power supply efficiency with more headroom and a cooler case. That headroom is exactly what makes DOE Level VI and CoC Tier 2 comfortable rather than marginal. For the broader case, see our guide to GaN power adapters beyond phone chargers<\/a>.<\/p>\nEfficiency is not the same as safety certification<\/h2>\n Buyers sometimes confuse the two. Efficiency rules (DOE, ErP) govern wasted energy; safety certification (CE, CB, FCC, and the underlying IEC 62368-1 style standard) governs that the supply will not hurt the user. A supply must satisfy both, and they are tested separately. A supplier should hand you both reports, each naming the model.<\/p>\n
What to ask a supplier<\/h2>\n
\n\n\nQuestion<\/th>\n Why it matters<\/th>\n<\/tr>\n<\/thead>\n \n\nWhich efficiency rule does this model meet?<\/strong><\/td>\nConfirms DOE VI \/ EU ErP, not a vague claim<\/td>\n<\/tr>\n \nCan you show the efficiency report?<\/strong><\/td>\nModel-specific, not a family average<\/td>\n<\/tr>\n \nIs safety certification separate and current?<\/strong><\/td>\nEfficiency \u2260 safety<\/td>\n<\/tr>\n \nDoes the report name my exact model?<\/strong><\/td>\nA family cert may not cover your SKU<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n