Packing List:universal rechargeable Li Polymer Batteries (Please full charge the battery before using it, It takes about 2.5-3 hours to fully charge the battery)Battery Specifications: Voltage: 7.4V, Capacity: 3000mAh, Watt: 16.28, Type: Lithium Polymer, Model: SWB01, Weight: 80g, Dimentions:(L/W/T)2.3/1.5/0.4inches.Our batteries are resistant to low temperatures, can be used in an environment of minus 40 degreesApplicable Products: Use for heated knee pads, heated gloves, heated socks, heated ankle wraps heated hats and other related heating productsCharging Port Type: 35135 DC Jack (outer diameter 3.5mm, inner diameter 1.35mm). If you need a charger, please purchase the charger separately: asin: . Only use the FEETMOR charger to charge the batteryBattery Working Time: The battery will reach its best performance after 3-5 full charge cycles. The battery can operate for 2.5-7 hours at different heating levels. Battery life: 500-600 charge cyclesBattery Storage & Care: When clean the heating product or charge the battery, please remove the batteries from heating product. In order to effectively maintain battery working time, please charge the battery every six months when not in use.Please store batteries in a dry indoor environment