By Erik Dolson
When I bought the 25 year old boat, I was completely ignorant of electrical systems and the boat had three battery monitors: One in the charger /inverter (charges the main or “house batteries when connected to “shore” power, or takes direct current from the batteries and turns it into alternating current for appliances), one in the master switch panel, and a small round monitor labeled “Balmar” that only retired Balmar Inc. techs remembered and for which Balmar has no information anywhere. I asume it was sourced from another OEM.
None of the three ever agreed with either of the other two as to voltage or current. And, I wasn’t sure if the little round guage wasn’t actually connected to the battery that was used to start the engine, given that unlabeled wires run everywhere.
Let’s not get into the two huge alternators that hung off the main engine and were driven by two too small V-belts impossible to adjust, and a dumb regulator. Boy, did they eat belts. Even a Blalmar smart regulator didn’t cure that (a serpentine belt, did, with one larger alternator. Sometimes you have to KISS a problem away).
Oh, the generator regulator was installed such that the “dripless” shaft seal could toss salt water right at it. Talk about random issues! Burnt wires! The generator exhaust was plumbed into a cockpit drain, which allowed engine noise and diesel smoke unimpeded access to the cockpit during evenings at anchor. The tachometer didn”t need to be replaced despite the insistence of a tech who aparently didn’t grasp open circuit vs volatage under load, and the main engine would not start for a while in Alaska until, again, contacts were sanded and tightened.
So, if three guages don’t tell the same story, get a 4th! Bought a Balmar Smart Guage and wired it myself to one battery of the house bank so that I would absolutley know where and how. This battery monitor agreed with the voltage of the round Balmar guage which also gives amps draw. They were consistetly .2 volts higher than the old panel monitor, which also seems to report amps randomly between 2 and 200, which I put down to age/shunt issues, and a refrigeration system that does not go through the main panel at all but is wired up somewhere in the engine room. I’ll find the connections eventually.
But as long as things were working and somewhat consistent, I wasn’t worried. I was ignorant, almost as good!
That left the charger / inverter, which agreed in volts with the two Balmar guages when it was not charging, but was way off when it was. It also was not fully charging the batteries from shore power, I realized later, though my main engine and generator did, once new regulators were installed. The charger / inverter started to behave once a loose ground was tightened up during the process of sanding engine room electrical bus bar connections.
Then came solar, and the panels, and solar controllers, and a battery sensor that doesn’t broadcast beyond it’s own low profile shadow, and hence even more discovery.
It’s amazing to me how frustrating this can be, but at the same time, how much I love this stuff! I really mean that. What an education!
Like discovering after almost threeee yeeears and uncountable episodes of wiping up diesel while chasing the perfect flame that my Dickenson Diesel Heater doesn’t just want good draft, it really prefers positive cabin pressure! What a hoot!