Solution:
Slow charging is 99% a faulty USB charging connector.
I have tried brand new Samsung cables, Brand new Blackberry cables and knockoff cables (Not all Micro USB cables are the same)
U Most likely will find a USB cable that will give you a high rate of charge most of the time because the USB port on the device is worn out (ie: ONE MUST FIT EVENTUALLY)
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galaxy charging current LITE ( I STRONGLY recommend purchasing the PRO version because it auto refreshes) the max voltage on the app is 999-1000mA.
Open the app (I have the pro) and when you connect the cable to the device watch the voltage (you have to hit refresh on the Lite version) if when the app refreshes and the voltage drops below 1000mA but remains stready when the cable is shifted or the device is moved (Eg. drop to 600mA) then discard that cable.
If the voltage fluctuates as the cable is shifted or the device moved then
replace/ repair the USB charging port. It is also recommended once opening the device to check the charging circuit
Resolving Samsung Galaxy S3 charging problem.
Also download
Battery Monitor Widget to monitor the battery flow. Once the device is charging properly on a 5V - 2Amp charger then the battery flow WILL ALWAYS be green and positive (
+918mA) and Red and negative with not charging properly (
-634mA)
This is the information i have complied and used to fix my slow/erratic charging problem. I hope this helps.