BiXPower 36V 14Ah (or 504 Watt-hour) Electric Bicycle E-Bike High Capacity Light Weight Lithium Ion Battery -BiXPower BX3699 High capacity: 36V 14Ah ( or 504 Watt-Hour) capacity. Made with high quality Panasonic lithium ion battery cells. This battery is for professional users with advanced electric knowledge only. It can be used for 500W or less power motors. Light Weight: only around 5.5 pound. A similar capacity Lead Acid battery may weigh around 30 ~40 pounds. Small size (9.8" x 4.4" X 3.0") makes it easy to fit on many different place on bike. Very powerful: continuous output up to 450W ~540W. High quality: made with premium Panasonic Lithium Ion cells. High Durability: Water-resistant and firm ABS plastic casing. The internal pack is stabilized by braces. Built-in PCB protection to prevent short circuit, over-current, over-heat, over-charge, over-discharge. The internal pack is stabilized by braces that can avoiding mechanical accidents caused by vibration.