Ecotric 36V 13ah lithium battery for 26 inch fat tire Beach and Snow, Leopard and Vortex ebikes. If you have a 26 inch fat tire Beach and Snow ebike or a Vortex, you should check your battery carefully to confirm if it is our latest model. If you don't know, please send the photos of your old battery to our email: support@worldofebikes.com and we will help you select your battery.