Two rechargeable batteries help you double the charging efficiency and shorten the waiting time | The smart LED charger display the battery charging level real time to prevent your from frequent guessing how much your battery have been charged. it can charge either two batteries simultaneously or 1 battery from any USB Power source | The battery cell features four layers of protection (over-charging, short-circuit, high-temperature, and surge protection) with a high-quality, Fire-resistant construction | With one Micro-USB port and one Type-C port, the batteries can be charged with wall charger, car charger, power bank or other charging option. Instantly switch to charging mode within 1s by inserting the batteries, hands-free | 2 year warranty and lifetime service