Why won't my phone fast charge while on, but only when its off?

[AC Question]

Why wont my phone fast charge while on, but only when its off

My phone as of late has trouble charging when its on, even when its in ultra power saving mode, it took 4 hours to get to 90% charge from almost dead. While its off it has no problem charging, so I feel its some of the 3rd party apps that I've downloaded but I dont know how to tell what is drawing all the power or whats stopping it from charging properly while being on.

 

[Rukbat]

Re: Why wont my phone fast charge while on, but only when its off

Start in safe mode - that starts with no 3rd party apps running. Check (for a minute or two) whether it charges normally. If it does, run a 3rd party app that normally always runs and check again. Kill that one and run a different one. Over and over. It's a long process, but it's the only way to find out which 3rd party app is causing a problem.