Sub title: Why I feel for anyone with an electrical problem on their boat.
That's right, today I found that the power conditioner for our marine stereo was sucking down more than 2.5 amps - every hour of every day, all summer long. The power conditioner is there so if you turn the stereo on, it can supply clean power to it.
Power conditioner with the case slightly opened
Case fully opened
It was wired directly into the main power switch on our house bank. Since our bilge pump is wired into the main breaker panel, we needed to leave that main switch on to make sure the automatic bilge pump/switch worked. That means all summer long, the equivalent of a 30 watt light bulb was continuously on. For reference, we have a 40 watt solar panel, which puts out about the same amount of power when the sun is shining.
When I discovered this, I was amazed. Stunned even. Today was the greatest single day working on our boat. I really felt a great accomplishment finding this.
Here's a (16 Meg) video showing the change in amps, after I re-routed the power conditioner through the main breaker panel and the stereo switch (so it would show up on the moat's amp meter). I put some other electric things on, to get onto a good part of the boat's amp meter.
Video that shows the power drain (16 megabytes)
Here are the details...
I went to the boat today to try to track down why the starting battery (not the house bank) was always low on voltage this past summer. So I got my trusty, handheld amp meter working and set-out to understand what all the wires do, that connect to our 3 main switches (house bank, starting battery, ground). I left the ground side for another day and focused on the house and start wiring.
Here's what else I learned:
1) The starting battery was directly wired to the 35 watt spreader-type light that was mounted on the transom for use in boarding at night. This light was rarely left on, so the cause of the drained starting battery is still a mystery. Last weekend I replaced that light with an IllumaDeck LED (spreader-type) light, so it now draws 0.106 amps. I shifted the transom light's wire to the house bank. (When part way home tonight I realized that it needs a fuse. I don't think there is one on that wire.)
2) One of our man breaker panels was wired directly to the house battery and not though the main switch. Fortunately that small breaker panel is only used for the wash down pump that I fixed a few weeks ago, so it's rarely used. I shifted that wire to the main switch. (Because it was wired directly to the positive side of the battery for years, there's a bit of corrosion around the crimped lug. Guess I need to get a crimper for 6 gauge wire, cut a few inches off the wire, and re-do the connection. Anyway, I taped it up to cut down on future corrosion.)
3) The voltmeter on the circuit breaker panel draws 0.126 amps when you throw the switch to measure one of the battery's voltages. While that's not a lot of power, it adds up to more than 2.5 amp-hours per day, so it's important to not leave the switch on and measuring voltage all the time.
4) There are 2 wires leading from the hot side of the main switches, that have 0.0035 amps going through them 24x7. I think they might goes back to the alternators, but I'm not sure. At least there's some type of relay near the alternators with similar red wires. That's an avenue to explore another day. It's really a small amount of power, so I'm not as worried about the power drain from those.
Oh, and the power conditioner for the stereo that was wired directly to the house bank? I wired it to the circuit breaker for the stereo, just like the stereo control wire like that also goes into the power conditioner. It meant creating a "Y" wire with 1 male and 2 female plugs on it. Here's my creation.
I made it by stripping the center of a 14 guage wire, removing 1/3 of the wires, trimming the insulation back at an angle and then folding the wire in half, so the folded wire went into a crimped male connection and the insulation from both sides fit into the strain relief part. I didn't have any red wire, so I covered it in red electrical tape.
Finally, I took the wire that originally went to the power conditioner and disconnected it from the battery bank. Then I labled it and left it in place in case I ever need a pre-run spare connection. (As seen below, the label is on white paper held in place with a little bit of duct tape.) Maybe I can use the wire when I re-run the bilge pump wiring so it has a direct connection to the hot side of the house bank. Once I get that re-wired, I won't have to leave the main switch on all summer.
Here are the wires at the main switches.
It may not look simple, but it all makes sense to me now. That is, except for those two 0.0035 amp wires.
By the way, I actually like doing this type of thing. It's like a puzzle of sorts.