As one might surmise, not much of the mechanical and electrical
systems in this boat are original with plenty of DIY fixes over the decades. We working on a "modest" nut reasonable budget
. We have discovered some inconsistencies relative to the boats charging systems that result in insufficient charging of the house batteries.
3HM 27 HP diesel
Hitachi alternator (most likely a LR-155, but it's ID label was painted over during a engine
rebuild) with internal regulator that was recently tested to be putting out 45 amps.
While the single
starting battery and the 2 house batteries are all flooded acid batteries, they have little else in common ("one house battery" is actually two 6V batteries wired in series),
The 1/both/2/off battery selector switch currently switches between the two house battery banks,
There's a 3-post, diode isolator that distributes the alternator's charging output to each battery bank, but the alternator's sense wire is the original wiring
off the ignition switch.
The shore power
is smart and can charge up to 3 battery banks. It's charging output leads are currently connected to the battery posts on the isolator.
panel is directly connected to one of the house batteries.
Our (perceived) challenges:
#1. The alt is sensing only the starting battery's charge, so when that battery is fully charged the alt effectively shuts down thus not fully charging the deep cycle house batteries.
#2. We'll never truly know what model Hitachi alternator we have due to the "nice" paint
job, it seems to putting less amps than it's rated for, it's internally regulated, and generally believed to as a fellow sailor stated "not worth a pile of mouse poop".
#3. We're woefully ignorant as to how to effect improvements to this mess.
#4. The charging system is probably got more small, unaccounted for voltage drops due to the hodge-podge of cables
My humble thoughts:
#1. We should replace the current
alternator with a good externally regulated model.
#2. Based on #1 above, we'll need to acquire a external, probably smart, voltage regulator/monitor and/or something else that monitors, prioritizes and charges all the batteries fully.
#3. Disconnect & remove the diode isolator totally.
#4. Connect the shore power
battery charger directly to each battery bank.
My 20 questions:
#1 Anyone care to take a shot at ANYTHING I've written so far, particular the tentative fixes?
#2 Assuming an alternator replacement is a must, any recommendations for brands, sizes, regulation method, etc.
#3 Assuming a new externally regulated alternator, any thoughts/recommendations for what to buy? How to sense which batteries need charging? How best to save/reserve the staring battery?
#4 Best method for connecting in the shore power charger and the solar
#5 Should the battery selector switch switch between either of the two house batteries or between the house bank and the starting battery?
#6 Anyone know any experts in these matters close to Punta Gorda, FL?
#7 What have I missed? Any additional thoughts, suggestions, recommendations or worse?