Going forward, the new voltage levels to expect on new chargers are 5V, 9V, 15V, and 20V. The 12V level is now optional.

The new rules also introduce a “superset” guarantee. Larger wattage power sources must support all voltage levels below their maximum up to 3A. As the spec says, “Bigger is always better in user’s eyes – don’t want a degradation in performance. Higher power Sources do everything smaller ones do.”

As a result, the consumer only needs to know that their device ships with a x watt power supply, and know that any power supply that is rated at > x watts will be at least as good as the one that shipped with the device. When comparing power supplies, they only need to look at the watt rating to know when a charger is objectively more capable than another. Under no circumstances should a more expensive charger charge your device slower than a cheaper one.