So recently my S4 has been charging incredibly slowly, I decided to install a quick app (Galaxy Charging Current) to monitor the current output from my charger. I'm using the standard S4 charger that came with it which is supposed to deliver around 2.1A. I do understand that it'll never deliver quite as much as 2.1A due to current drop in the cable etc, but I was shocked to see 300mA being delivered to my phone which would take hours and hours to charge my phone to completion. In fact, I left my phone on charge overnight from about 15% and woke up 9 hours later to 53%, in the battery settings it showed the charge decreasing and increasing by increments.
And so I believed that something with the charger was wrong, so the first thing I did was try out two different USB cables for my charger and then test to see if the current had changed, it had not it was still at 300mA. I ended up buying a new stock S4 charger but the issue persists. However, with this new charger it outputs 1890mA at times, but then drops to 300mA randomly for periods of time. I've tried different wall sockets as well.
Anyone else had anything similar or could offer advice on why this is and how I can change it?