I've had Evo's the last four years (first the original Evo, then the 3D) so I have two original Evo chargers, a travel charger, a car charger, etc. Does anyone have an idea if I can safely use these with the S4?
Yes, newer phones have a regulator built into the device/battery that will safely stop charging when it is done charging. Nothing is controlled by the actual wall unit. That being said.... if you plan on getting an S4 I would probably say get another OEM one online, usually they cost next to nothing and work just as well if you want to be cautious. I have been using old BlackBerry chargers from when I had a BlackBerry Curve to charge my devices with no issues.
Thanks very much. I will probably get one extra official anyway, but one of my favorite things about the Evo chargers is that they were interoperable with each other, and also with my Kindle. It's nice taking one less charger with me for travel.