Question: What is the input voltage if you plug into a power outlet? 110 and 220v?
Answer: Input is 5V DC. It comes with a USB2 cable.
Question: I own this charger, but I’m paranoid that if I leave it on the charger (after fully charged) that it
will overcharge and break. Could this happen?
Answer: Never, the charger will automatically turn itself off for overcharge protection when it gets fully charged.
Question: Which port is the fast charing port? and, how can you tell?
Answer: You can see it in the photo that shows the back of the charger. Behind each port there is a little lightning bolt symbol.The port that has two lightning bolt symbols behind it is the faster port (5V/2.4A).