July 6, 2017

LG G6 - Quick Charge 3.0 Not Working?

I finally got my G6 to charge properly with Quick Charge 3.0!  Here is what I learned...

The following conditions must be met, or else the G6 steps down power during charging and you will not get a proper QC 3.0 charge:

  • battery must be below 80% capacity
  • screen must be turned off
  • screen saver mode must be disabled

The LG G6 has a Snapdragon 821 SoC that supports Qualcomm's Quick Charge 3.0 technology for rapid charging. However, I haven't been getting very fast charge times on my G6.  I tried the stock charger/cable and even several QC-compatible 3rd party accessories.  While the G6 showed a "Fast Charging" notification, it didn't seem very fast at all.  It also seemed to charge faster over wireless (Qi) than with a charger and cable attached!

So I bought a QC-compatible USB multimeter to test the voltage and current the G6 was drawing during a charge.  Just as I suspected, I was *not* getting a Quick Charge at all.  The adapter that comes with the G6 is supposed to be able to charge at 9V/1.8A, but I couldn't see it draw anything beyond a 5V/0.5A.  After much frustration and troubleshooting, I realized I had my G6 configured to run Screen Saver mode during charging.  After disabling the Screen Saver, I finally saw it charge at the full 9V/1.8A!

Also note:
  • when the "Fast Charging" notification is displayed, it just means a QC compatible charger/cable was detected, not that it's actually charging at QC 3.0 speed.
  • Screen Saver setting is located at: Settings > Display > Screen saver