You may want to check the charging amps on the charger that you are having problems with before you go searching for a different cable. There are apps on the market that will show what your charging amps are. I have (what used to be) a good charger that charges my S4 very slowly. It only reports 800mA when charging. I bought a new, two port charger like you described and it reports 1900mA for charging and charges the phone quite quickly. The Mains Charger that comes with the Galaxy phones charges at 1900mA also and charges the phone quite quickly, even with the long thin cable that was provided with the phone.