I've had some pretty mixed luck trying to charge my Lumia 950 from various sources. Charging directly from the AC to USB adapter that came with the phone seems to be fairly reliable. But plugging into nearly anything else via the USB A to USB C adapter usually ends up being slow or not working at all.
I'm guessing this probably has something to do with the new USB Type-C connection, and varying power requirements that come with the new specification. I know there's probably some information that could be gleaned from the USB standards themselves, but we can't always trust manufacturers to adhere to those specs - and, ultimately, a device requires and can only tolerate what it's designed to use regardless of what the standards "allow".
The AC charger that came with the phone says the following about its input/output:
- 100-200 V
- 50-60 Hz
- 0.40 A
- 5 V
- 3.0 A
Do I really need to get adapters that exactly meet the Output specs of the original AC adapter? Or will the Lumia 950 charge reasonably well with a weaker supply? One of the supplies I've particularly had problems with has a 1 A and 2.1 A port, and neither seems to work.
What are the minimum requirements? Are there any maximums I should refrain from exceeding?