USB Power Bricks

On the topic of USB, Power

Most if not all USB-A bricks have a fixed power rating. A common output is 5v 1a. I've seen some 2a and 12v bricks too.

For USB-C, this is different since most if not all USB-C bricks implement something called USB Power Delivery, or USB-PD for short. PD comprises of a set of rules where the device asks the brick for the power that it needs.

Some consider it a hack, but it's official spec that having a 5.1k resistor on the CC1 and CC2 lines of a USB-C port will result in the brick delivering 5v at 1.5a (or 3a depending on how the wind blows) of power. If you need more, you'll need an IC to do the negotiation for you.

Of course, a cheap USB-C brick might shit out whatever is on the label instead, so always double check. However in 2026 it's unlikely to find a USB-C brick that doesn't use PD.

If you find that your USB-C device is not charging on a USB-C brick, it could very well be that it's expecting a dumb USB-A brick instead. Of course, always check the ratings on both the brick and your device to make sure you don't accidentally connect to a 12v brick when your device is expecting only 5v.

I ran into this issue with a cheap USB-C connector from AliExpress. Flabbergasted that my USB-C brick didn't work.