Sinrace Power Supply Technology (Shenzhen) Co., Ltd.

Third-party manufacturers address the problem of diversity with aftermarket "universal AC adapters" whose voltages and polarity can be adjusted, and come with a variety of DC plugs. The user must examine the appliance to be powered, attach the correct plug, and adjust the "universal" wart correctly to make it work properly and avoid destruction by incorrect voltage or polarity. Labeling seldom mentions the need for a particular degree of ripple filtration, voltage regulation or other questions of power quality, assuming that no user would attach a "foreign" power adapter and effectively leaving such matters to chance.

USB hubs may be used, even in the absence of a computer, to power certain kinds of consumer equipment known as "USB decorations" which are intended to be powered by a computer. Such devices are bound by the half amp (2.5 watt) USB limit. Being in general non compliant to the USB standard, they may interfere with the computer peripherals for which USB was intended. Several manufacturers agreed in early 2009 to make mobile phones powered by micro-USB, thus freeing users from dependence on proprietary warts and battery chargers.

Powered USB replaces wall warts for certain commercial applications, with only three different kinds of plugs for 5, 12 and 24 volts DC, thus preventing plugging in the wrong voltage. It is especially commonplace in POS terminals but is not used for consumer equipment.

A "Green Plug" system has been proposed, also based on USB technology, by which the consuming device would tell the supplying wart what kind of power to supply.[2]

Larry Page, a founder of Google, has proposed a 12 volt, 15 amp standard for almost all equipment requiring an external converter.[3] New buildings would also have 12 V DC wiring, so that in effect the wart would no longer be outside the wall.

Car batteries (12V batteries) can also come in handy as inexpensive batteries to power car adapter devices with an alligator-clip-to-receptacle Y-cable connected to a universal voltage changer since it would provide similar functionality that doesn't waste valuable AC power.