Here’s how long it takes to charge a cell phone: The answer depends on many factors, such as the capacity of your battery and the charger you are using. Modern smartphones generally take between 40 minutes and two hours to charge. These are just averages because real charge times vary so much, even between phones that are from the same company and model. If you want to learn all about how long it takes to charge a cell phone, then you’re in the right place. Let’s jump right in! What Is the Battery Capacity of Your Phone? The first thing to understand about phone charging is to understand what exactly we are charging. Batteries, more specifically lithium-ion batteries, power modern smartphones. These batteries store energy in the form of chemical potential energy. And when that energy is needed by the phone to work, this chemical potential energy is converted into electrical energy. This flow of energy is power. This is the power that runs all the little circuits and display screens on your smartphone. But like any source of power, this is finite and limited. Once there is no more chemical energy to convert to electrical power, your phone dies. On another note, learn here all about whether your cell phone goes straight to voicemail when your battery dies. Getting back to the topic: When your phone dies, charging comes in. Charging your phone is the reverse process of the one I just described. Now electrical energy from your outlet is converted into chemical potential energy to be stored. Charging a battery can be thought of as filling up a tank of gas. If we take this analogy, we can better understand how long it takes to charge a phone fully. So, for example, a smaller tank will take less gas and less time to charge. While a larger tank will take more time and more gas to fill up.