What size fuse is recommended for the inline holder? Shawn January 10, 2017 17:38 The SR-955HPC, SR-655HPC & SR-447HPC2 use a 15 amp fuse. Related articles Fuse size (amps) for SR-497HPC? SR-655HPC Setup Guide Can I power the 655 with a cigarette lighter adapter? How many amps does the SR-955HPC radio draw? SR-955HPC Manual Comments 0 comments Article is closed for comments.