$Id: usb-pd-voltage.malblog,v 1.6 2021/12/26 17:12:15 homer Exp $
| [ | Date | | | 2021-12-26 12:12 -0500 | ] |
Some USB-C chargers I have used, in order of increasing total power:
| Model | 5V | 9V | 15V | 20V | Dell-OK³? |
|---|---|---|---|---|---|
| Apple 20W | 3A (15W) | 2.2A (20W) | - | - | n |
| Google 22.5W | " | - | - | - | n |
| Samsung 25W | " | 2.77A (25W) | - | - | n |
| Apple 30W | " | 3A (27W) | 2A (30W) | 1.5A (30W) | Y |
| Samsung 45W | " | " | 3A (45W) | 2.25A (45W) | n |
| Apple 61W | 2.4A (12.5W)¹ | 3A (27W) | - | 3A (61W)¹ | Y |
| Ravpower 90W² | 3A (15W) | " | 3A (45W) | 4.5A (90W) | Y |
The marker " means “same value as previous row”.
¹: Labeled with unusual voltages 5.2V and 20.3V instead of 5V and 20V.
²: Also supports 12V at 3A (36W).
³: The “Dell-OK” column indicates whether a given charger can charge a 2016 Dell XPS13. Since that laptop’s original non-USB-C charger is 19.5V / 2.31A, I would have assumed that the ability to deliver 20V would be the discriminating factor between supported and unsupported chargers, but apparently not, as the lack of support of the Samsung 45W charger shows. The computer was produced at a time where support for USB-C Power Delivery (PD) was nascent, so spotty cross-support is perhaps not surprising.
The two-port Google 22.5W model supports only a maximum of 15W on single port, and claims that “the device that needs the most power is automatically charged more”. Conversely, the Ravpower 90W two-port charger support the full 90W on either port.
I don’t know how multi-port chargers communicate with devices to decide how much power each one deserves.
Some of the newer chargers support a PPS (programmable power supply) mode, with finely adjustable voltage at a given, fixed intensity. Apparently, this is useful for batteries which charge best at fixed intensity.
| Model | PPS intensity | min voltage | max voltage | max power |
|---|---|---|---|---|
| Samsung 25W | 3A | 3.3V | 5.9V | 17.7W |
| " | 2.25A | " | 11V | 24.75W |
| Samsung 45W | 2.1 | " | 21V | 44.1W |
| " | 2.8A | " | 16V | 44.8W |
| " | 4.05A | " | 11V | 44.5W |
Quick links:
David Haguenauer
<www@kurokatta.org>
$Id: usb-pd-voltage.malblog,v 1.6 2021/12/26 17:12:15 homer Exp $