Why is my Nintendo Switch Charging So Slowly?
Disclaimer: The Nintendo Switch apparently isn't compliant to USB Power Delivery (USB-PD) standards and may damage the charger or even itself. The same applies to the official charger. Therefore it is safer to only use the official Nintendo Switch charger, and only to power the Nintendo Switch itself.
The charger you're using may not provide enough power for your Switch to charge quickly. This is the case with most smartphone chargers.
The official Nintendo Switch charger provides 2.6 A * 15 V = 39 W, which is used to charge the Nintendo Switch battery while supplying the extra power needed to run games at a higher framerate/resolution on TV.
By comparison, the charger for a Sony Xperia XZ from 2016 provides only 1.5 A * 5 V = 7.5 W, which is not enough to charge the Nintendo Switch battery while playing games, but is enough to charge the battery slowly while on Standby.
Meanwhile, the charger for a Microsoft Lumia 950 XL from 2015 provides 3 A * 5 V = 15 W, which may be enough to charge the Nintendo Switch slowly while playing, depending on the game.
For a more recent comparison, the iPhone 11 Pro Max (2019) used to ship with a 2 A * 9 V = 18 W charger. I have not yet tried charging the Nintendo Switch with it, though I've tried a 96 W charger for the 16 inch MacBook Pro (2019) without any discernible difference from the official charger, though I've only ever used it once for a short amount of time. The 96 W charger supports 3 A * 15 V = 45 W and 4.7 A * 20.5 V = 96.35 W among others. I'm not an electrical engineer, so I don't know if supplying a device expecting 15 V with 20.5 V instead is dangerous or not. Luckily, @Bob has an answer to that in the comments:
It is most definitely dangerous, but then the whole point of USB-PD is that the source and sink negotiate the voltage. The source will not be supplying 20 V unless the sink explicitly requests it. So, while supplying 20 V to an arbitrary 15 V device is dangerous, using a USB-PD source that supports up to 20 V with a 15 V USB-PD sink is perfectly safe.
As mentioned before in my disclaimer, just because I managed to successfully charge my Nintendo Switch with most of the chargers mentioned above, it doesn't mean it wasn't dangerous or that my Switch didn't suffer damage. It may have suffered some damage I haven't noticed yet. Therefore I recommend using the official charger, unless you have reason to believe the Nintendo Switch has become fully USB-PD compliant.
USB-C throws most people on power requirements because prior versions of USB "just worked" when you plugged them in (i.e. micro USB, which is what most Android phones used until the last few years)
The base USB-C uses the older USB standard of 1-2 amps @ 5V. You'll note even the standard Switch chargers offer that. The reason for that is that immediately offering more amps or voltage could destroy the device. You can plug any USB-C device to a Switch charger and get a "slow charge" of 1.5A @ 5v. The inverse is generally true as well (with some caveats below).
If you do own a USB phone, however, odds are good they gave you one that will charge your phone faster than that. Qualcomm makes one called Quick Charge for phones, but the Switch uses something called USB-PD, which isn't the same (i.e. plugging your Switch to a Quick Charge device won't charge at a higher rate).
The catch is you need two things to do this
- A charger that supports the USB-PD standard
- A USB-C cable that fully supports the charging standard
Your device and the charger then negotiate a higher power delivery. The problem is there's lots of cheap non-standard stuff on the market that can fry your devices (especially a Switch). Exhibit A would be an early Nyko Switch charger
While a wide variety of third-party chargers and cables have been linked to Switch bricking, the most common complaints seem to center on a third-party dock made by Nyko. Like many cheap USB-C chargers, the Nyko dock does not actually have a dedicated PD controller; it instead implements the PD protocol using a general purpose microcontroller—and that microcontroller was sending 9V to the Switch over the CC pin, exceeding the absolute maximum voltage rating by 50%. And as they taught me in Electronics Technician A School in my Navy days, when you let the magic smoke out, the widget stops working.
And later
Finally, you may brick your Switch if you use USB-C to USB-A adapter cables. There are two variants of the cable; one with a 10K ohm resistor, and one with a 56K ohm resistor. This isn't directly dangerous to the Switch itself, but using a 10K ohm cable with a low-powered USB-A charger may overload it, damaging the charger—and a damaged charger could produce unexpected voltage on an output pin, which might in turn damage the Switch as well.
So if you're looking for a faster charge, I would do your homework and look for both a proper USB-C cable AND something that properly implements the USB-PD standard.
Different cables and USB wall adapters will provide different power output.
Try using the original dock and your charging experience will increase significantly.
As you say you've had the Switch three years, it may be time to clean out the USB-C slot with a toothpick.
USB-C sockets seem unfortunately prone to collecting dust, lint, and other kinds of gunk. You can sometimes tell this is becoming a problem if your charging cable "mushes" loosely into the charging socket instead of clicking in firmly.
A toothpick is a reasonable way to clean it out. Don't push hard enough to break the toothpick off in the slot. You'll still probably break a toothpick or two (it'll just bend at the end); when this happens, use the other end or discard it and get another toothpick.
I had a similar problem with my phone recently, which went from charging completely in 2 hours to only charging about 3-5% per hour, and eventually not charging at all. After scraping out quite a lot of pocket lint with a toothpick, the USB-C cable now clicks in firmly again, and it's charging good as new.