Milliwatt-hour Unit | All you need to know

A milliwatt-hour (mWh) is a unit of electrical energy equal to one thousandth of a watt-hour, or the amount of energy a one-milliwatt device consumes in one hour. The milliwatt-hour is standard for specifying battery capacity in portable electronics including smartphones, smartwatches, wireless earbuds, and portable power banks. Medical devices like pacemakers and implanted sensors also specify energy in milliwatt-hours. The unit produces practical numbers for low-capacity devices—most smartphone batteries range from 2,500 to 5,000 mWh, numbers that are easier to communicate and compare than 2.5-5.0 Wh.