Wireless charging is something that it is becoming very common lately. Most of Android phones are capable of charging wirelessly nowadays. For wireless charging to work, you need to have a charging pad connected to a power source. You leave the phone on the pad and it automatically starts charging. The issue with most phones is that the charging speeds are very slow. It takes a lot more to charge a phone wirelessly compared to the traditional way.
As a result, some manufacturers such as Samsung and Google have implemented an even better wireless technology called Fast Wireless Charge. Fast wireless charging is much faster than the normal wireless charging. The Google Pixel 3 and Pixel 3 XL can charge at 10W wirelessly using the Pixel Stand or devices certified from the “Made for Google” program.
The problem is that if you are using Qi-chargers that are not certified by Google’s program, the charging speeds are much slower. The Pixel 3 can pull only 750mA charging current on charging pads which are not certified.
Enable Fast Wireless Charging on Pixel 3 and 3 XL
If you have a Pixel 3 or Pixel 3 XL but only a non-certified charging pad, there is a way to increase the charging limit. Senior member “k0rner” has found a way to enable fast wireless charging on all Pixel 3 charging pads.
There is a control file in /sys/class/power_supply/wireless, voltage_max which has a default value of 5000000 (5V). This value can be changed up to 9000000 (9V). After changing the value, the charging current goes from 750mA all the way up to 1290mA, which is an increase of 72% in charging speed.
echo 9000000 > /sys/class/power_supply/wireless/voltage_max
# Now, check what we've got
grep . /sys/class/power_supply/wireless/voltage_*
voltage_max:9000000
voltage_now:8568000 # Means it has been raised by device
The value can be modified while the phone is wirelessly charging otherwise the file will refuse the changes. The modified value goes back to its original state when the charging session is over, but it can be changed permanently with a Magisk module.
If you are curious enough to do this, head over to the original thread post for more information.