Slow Charging Battery! I have a Samsung galaxyS3 the battery has been charging really slow. It can take up yo 10 hours to charge 100%. I have tried every thing I can think of. I've tried a new charger, new battery, shut down all apps running in the backgrond, taken out the battery and held down the power, volume and home screen button, deleted junk apps. I've thought about reseting my phone but idk if that would help or just make more work for me. Also I put both my old and new battery in a friends phone and both batteries worked fine. Any ideas?
It might be worthwhile to invest in a charge only cable. I use one for my tablet at home and in my car. 

The quality of the usb cable will also make a difference. Cables do go bad. It sounds like you have ruled out all the other options so this might be worth trying.