9 Volts Lithium Battery: 9V 6600mAh 6800mAh lithium battery provides long-lasting power output. It can stably output 9V voltage during use, making it suitable for many different devices. Advantage:Eco-friendly and saves money than normal batteries, the rechargeable battery is economical for frequently used devices, significantly decreasing waste and pollution to our environment. Safe Protection: Each battery has polarity protection such as overcharge, overdischarge, overvoltage, overtemperature, overcurrent, short circuit and undervoltage. USB Charging Design: The rechargeable lithium-ion battery has a built-in Type-C USB port, allowing you to recharge from PC, computer, wall socket, power bank via USB charging cable including. Long Battery Life: The rechargeable battery has a long battery life due to its long durability, which can be recharged more than 1000 times.Rechargeable battery can be fully recharged in 1-1.5 hours.