My dedicated starting battery is sitting on a shelf that I added in the space just forward of the forward 4D in the starboard side settee. As a slight port list is typical for many C-320 owners and the space is ample for the purpose, this is a favorite location for many later model C-320 owners where the batteries are located under the middle of the starboard settee. This location is also desirable in keeping the new jumper wires short which reduces resistance and voltage losses.