I recently experienced my starboard battery not holding a charge and the house lights (12 volt) flickering. After charging and load testing the battery, I found that the battery was ok but the converter charger was only putting out 8.6 volts (the port converter charger was putting out 13.6 volts). Now, the research began.
The converter charger was a Triad-Utrad TU-323 20 amp system. There was one for the port and a separate one for the starboard. My Commander has twin Detroit diesels with an 8d starter battery for each one. There is also a group 27 battery for the generator but NO house batteries. This had always baffled me but I was told the starboard engine start battery was in fact my house battery. When diagnosing the problem, I found that the converter chargers were connected to the electrical box for the corresponding engine with an 8 gauge wire. The voltage/amperage from the converter charger split with the positive going to the battery and also to each side of my DC fuse box. The ground from the converter charger connected to the ground block under the engine.
I was looking at all the new multiple battery smart chargers on the market (of which there is a bunch) and was leaning toward a single Pro-Mariner. 3 battery system ($589 on Amazon) that would keep all 3 batteries charged (the generator battery is only charged buy the generator directly). However, with each of the smart chargers, I would have to run it directly to the batteries and increase the size of the cable from the current 8 gauge to a 2 gauge to support the increased amperage. I would also have to put in fuses or circuit breakers at each of the batteries in the charger line. A big change from the wiring I currently have. So, more research.
I finally found a manual for the TU-323 and realized what a converter charger really did. It is more than just a battery charger. It takes the 110 volts from shore power/generator that is converted to 12 volts and allows you to directly power the house without going through the batteries (that’s why there aren’t any house batteries). So, if I disconnected the batteries, my 12 volt house would still work if connected to shore power or the generator is running. When not connected to shore power or operating the generator, the house is powered by the engine starter batteries (not ideal but that’s the setup Chris Craft put in). With the regular smart charger, you have to have a battery installed and the house is powered through the battery. So I started researching Converter Chargers and found there are fewer options than with the other smart chargers.
I finally settled on a Progressive Dynamics PD9245CV Inteli-Power 9200 Series Converter/Charger with Charge Wizard - 45 Amp - https://www.amazon.com/Progressive-Dynamics-PD9260CV-Inteli-Power-C...
This operates as a converter like my TU-323 did but also has smart charging capabilities like the other smart battery chargers so, the best of both worlds. They installed easily, right where the TU-323’s were, connected to the 8 gauge wire already installed (I had less than a 10’ span of wire to the junction box) and, by adding a female plug to the power source, plugged in and functioned perfectly. Simple, way smaller and lighter than the TU-323’s and way quieter.