I'm confused about the resistances of common electrical appliances. v=ir So I was reading something about how fast iphones charge with different chargers and it got me thinking about the resistance of things like phone batteries. So it said that it could charge at 5V and 2 amps, but also at 5V and 1 amp.. So does the resistance change from charger to charger? Resistance = Voltage/Current right...so is the resistance for one 2.5 and the other 5 ohms? If that's the case...what would happen if I tried to charge, say, an iphone battery with something that charges a 2.5 ohm load at 1W? Would it depend on the charger connecting the two orr..... I'm confused ._.