USB-C charging cable enables easy charging You can charge all batteries simultaneously or individually, just plug it into a laptop, power bank, wall charger or car charger. Fast charging time is 1.5 hours, and the usb rechargeable batteries have indicator lights that blink when charging and go solid when done 2800mWh provides longer battery life It lasts 1.4X longer than other aa rechargeable batteries, in an game controller they work great, and don't worry about running out of power while you're playing Advanced explosion-proof & leak-proof technology After a number of safety tests, the rechargeable aa batteries usb c is as safe as the built-in charger for cell phones and computers, and you don't have to worry about harming your expensive electronic devices Recharged at least 1000+ times Multiple charges barely lose capacity, in the long run they will save you money on battery purchases and also reduce your environmental impact throwing away disposables Ve