I have bought two usb cables form ebay for G300 because my previous cable's (provided with the phone) lead was distorted a bit (works though). None of these usb cable charges the phone at the same rate as the original cable. The charging is very very slow and takes a lot of time to get a full charge. This why I bought a second cable thinking that first one was faulty. But both have very slow charging. Data transfer is fine with both. What is wrong with these cables?