My 2014 FC 20 did NOT have a 3 stage converter/charger. It had the standard Intellipower (spelling) 55 amp unit integrated with the 12 volt
fuses and a 120 volt section for the 120 V Circuit breakers. This is all located in a single box, in my case under the refrigerator.
I replaced the converter/charger section of the original assembly with one from Progressive Dynamics, which is a true three stage unit. I think it is a PD 46xx (xx indicates the amp capacity). Cost was about $200 as I recall, and included an entire new fuse block with little red LED lights that indicate if a fuse has blown. It is a worthwhile upgrade.