[Kavan Sidhu]

Simple question no need for detailed answers. My friend has tmobile S4 with cracked screen. It still works and is not to bad. But he wants to upgrade. He said he will sell me the S4 when he upgrades. But he does not have the original charger. I have a never had a Galaxy S4 before. My galaxy light is 1amp charger. But not familiar with S4. Was that also 1amp or did they up that to 2.1 amp?

[Rukbat]

It really doesn't matter. The phone will draw as much as it can, up to the maximum it was designed to draw. The OEM charger is 2 Amps, but I have no idea what the phone draws. My Note 3, which also came with a 2 Amp charger, draws 1.2 Amps. If the S4 is also designed to draw 1.2 Amps, it'll take 1.2 times as long to charge as it would with a charger capable of supplying 1.2 Amps or more.

[extraclass]

The S-4 will tell you onscreen when you plug in the charger, Use the Samsung charger for faster charging. I have found other chargers will charge just as fast but you have to use a suitable cable! If the lightning bolt is visible in the battery icon at the top of the screen you should be OK. The phone will charge slow if plugged into a USB port! You can find Samsung chargers on Ebay for about $10