When someone visits your website, you can easily retrieve information about the charge level of their mobile or laptop�s battery through the Battery Status API. Here the source code: <!DOCTYPE html> <html> <head> <title>Battery Status API Example</title> <script> window.onload = function () { function updateBatteryStatus(battery) { document.querySelector(#charging).textContent = battery.charging ? charging : not charging; document.querySelector(#level).textContent = battery.level; document.querySelector(#dischargingTime).textContent = battery.dischargingTime / 60; } navigator.getBattery().then(function(battery) { // Update the battery status initially when the promise resolves ... updateBatteryStatus(battery); // .. and for any subsequent updates. battery.onchargingchange = function () { updateBatteryStatus(battery); }; battery.onlevelchange = function () { updateBatteryStatus(battery); }; battery.ondischargingtimechange = funct...