Looking for an Harley Davidson FX/XL (K-START) battery? Then you've come to the right place. We have been selling batteries for Harley Davidson FX/XL (K-START) Motorcycles online since 2003 and will have the correct battery for your Motorcycle in stock, available for next day delivery. Use our Harley Davidson FX/XL (K-START) battery guide below to find a suggested battery for your Motorcycle and compare it to the battery fitted to your FX/XL (K-START). Need help? Simply contact us.