Keep a spare battery ready for compatible GOBI heated gear. The 6500-PD is a reengineered 7.4V, 6,500 mAh hard-shell battery with USB-C Power Delivery fast charging. The 6500-PD supports 30W PD fast charging and is specified to recharge in 3 hours or less. Runtime depends on the number of heating zones and the heat setting of the product it powers, so check that product’s listed runtime. Compatible with GOBI 5V, 7.4V, and 12V products. Check here to see if this is compatible with your GOBI item. https://gobiheat.com/pages/battery-compatibility-chart