If The Micro USB Charger’s Voltage Is Not 5v… Some devices may have their voltage listed with a plus/minus on it like this: 5v +- 5%. If this is the case, you can use a charger rated at 4.75 to 5.25v because that rating is telling you is that the device can take 5v minus 5% of 5v = 4.75 volts OR 5v plus 5% of 5v = 5.25 volts. So this means anything between 4.75 t0 5.25v is safe to use (as long as the amperage of the charger is equal to or higher than the device’s listed amperage). An interesting thing to note is all chargers supply a higher voltage than the batteries they charge. That is pretty much how they work. There has to be a voltage differential to produce the necessary current flow in the correct direction to charge the battery. If you look at your car, it has a 12V battery, but typical alternators provide 13.8 to 14.4V charging voltage to the battery. Stay Away From Cheap Knockoff Chargers The problem with knockoffs, particularly cheap knockoffs, is that they often don’t support the power requirements of the device, or are not built to maintain a steady flow safely. This can cause damage to the device but can also pose a safety/fire hazard. Overall, it’s best to stick with the charger designed for the device you are using. View our Free Presentation to learn how to bring old batteries back to life again