TopG Errand S1 4500mAh Ultra-Slim USB Backup External Battery Pack Premium Portable Power Bank Pack Charger for most Smartphones, Tablets and other USB-charged devices [18-Month Warranty] Ultra-slim, 4500mAh battery will charge your USB powered cell phone, tablet, action camera and other handheld devices on the go! The pack charges your device at a MAX rate of 1A NO MORE OVERCHARGING! Auto-Shutoff function kicks in when the device's battery is full Using premium quality lithium-ion polymer battery Built with a compact, travel-friendly design that can slip into your pocket, purse, or pack effortlessly Monitor power level easily through LED's. 18-Month Product Warranty.