I completely agree that it may not make sense to install a 110vac to 12vdc converter under the following circumstances:
(1) If you have relatively low 12vdc amperage needs. If like me, the total amperage of your interior LED lights
, fans, dc outlets, etc is under 10 amps, it may make sense to simply use a 110vac to 12vdc power supply or smart charger with a power supply mode setting (e.g., some NOCOs).
(2) If you already have or find a more suitable smart charger for your battery vs. smart chargers available with converters. For example, some converters are not designed to charge AGM batteries. Other converters do not provide sufficient continuous charging amps and/or voltage.
(3) Difficult to fit new converter into available cabinet space, as is the case in my Trillium
In my case, my Trillium
vintage DC converter failed. Rather than replace with a new converter, I removed the DC transformer and use a 110vac to 12vdc low amperage adapter. For charging my AGM battery, I use a standalone smart charger. I plan to add a switch for selecting DC adapter vs battery power.
In my Trillium
, I still use the vintage 110vac mains circuit breaker (may update this) and plan to add 110vac branch circuit breakers. Also, I still use the vintage 12vdc circuit breaker (may update this) and plan to add 12vdc branch circuit breakers.