I bought my s5 just recently. I first plugged in the phone to a different charger that the one it came with (if it makes a difference). The phone barely charges when in use and the battery is continuously draining even though it is plugged in and shows the charging sign. The battery percentage will only go up when its not in use or turned off. Even when it's turned off the charging is really slow (even with the charger it originally came with). I think the problem is with the usb port? I just bought the phone but its imported so i cannot use its warranty. How can i fix this?