Mini 12 volt battery (12N5.5A-3B) is a dry charged battery. For custom application on 1948-1964 FL Panheads. Battery has a right side vent position and and has a maximum charge rate of 0.6. Do not overfill battery, fill to the line level as noted. When refilling, use distilled water only. **NOTE: Requires filling with electrolyte acid, available from your local auto parts store.