I went back out on Saturday and added the voltage indicator to my HDS screen.
1. I had the dimming problem happen 2 of the 5 times that I restarted my boat. Both times, the voltage never registered a change while starting the engine but I had to reboot.
2. One time, upon starting the engine, the voltage dropped to 9.8v...this time the screen stayed bright!!!
I am thinking of adding a house bank (or single battery) to combat this and give me some extra "juice" to play the radio, leave the VHF/GPS on without stressing about the battery level.
24v DC / 24v alternator ---> 24v-12v converter ---> 12v switch panel ---> loads
-Currently have two 12v batteries in series powering the starter, nav lights, and bilge pump
-All 12v electronic (VHF, GPS, etc.) run off the 12v panel.
24v DC / 24v alternator ---> 24v-12v converter (existing) --->12v-12v battery charger (NEW ADDITION) ---> 12v house battery (NEW ADDITION) ---> 12v switch panel ---> loads
-I only found one 12v-12v batter charger while googling: DC Input Battery Chargers for 12 volt Lead Acid and SLA Batteries useful for electric golf trolley
-Cost: $154 + [1 x new deep cycle 12v battery]
24v DC / 24v alternator ---> 24v-12v converter/charger (NEW ADDITION) ---> 12v house battery (NEW ADDITION) ---> 12v switch panel ---> loads
-There are are a few of these out there:
12V battery charger with 24V input, heavy duty industrial, marine and military grade DC Input Battery Chargers for Lead Acid and SLA Batteries, for 12V batteries in 24V vehicles
-Cost: $300-$350 + [1 x new deep cycle 12v battery]
24v alternator ---> Blue Seas Add-a-Battery (NEW ADDITION)---> 24v House Bank (NEW ADDITION) ---> 24v-12v converter (existing) ---> 12v switch panel ---> loads
-The Blue Seas Add-a-Battery works with 24v systems: Add-A-Battery - PN 7650 - Blue Sea Systems
-Basically, I would have two 24v banks which charge simultaneously while the engine is on, and separate automatically when the engine is off. All 12v electronics would run off the house bank and, in an emergency, I could combine the circuits.
-I need to see if I have room for 2 more batteries! (One I can handle!)
-Cost: $100 + [2 x new deep cycle 12v batteries]
Comments about the above or other ideas are welcome!!! (and ask questions to clarify if I typo'd anything)