Over time, smartphone batteries have gotten bigger, and have started to charge faster too. While it used to be the norm to see batteries in the range of 3,000 to 4,000 mAh charging at 20W at most, it's common to see phones equipped with upwards of 4,500 and 5,000 mAh these days, charging at 45W and 65W. The ways manufacturers are cramming bigger batteries inside smartphones are getting ever more ingenious, and Samsung's latest idea seems to borrow a page or two from electric vehicles.