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Power draw at anchor

Thomas Peacock
 

We are leaving St Augustine for a month, and I am trying to get my electric usage to near zero. I could only get it down to 0.2 amps (as measured by the Voltmaster/Batman). All breakers are off (at least the ones I am aware of). I have taken the “permanent” Sailor 24>12 volt transformer out entirely, fuse removed. I then noticed that the fuel gauge still works. I could not trace the wires. There seems to be 19 volts at the gauge, but one of the hot wires comes into a resistor. If I disconnect the feed, the boat power usage does go down to 0.1 alternating with 0.2.
Two questions:
Any idea where the fuel gauge gets its power from?
Any idea how to get the amps down to zero?
Thanks as always to all in this group.

Tom Peacock
Aletes SM 240
St Augustine Florida

Craig & Katherine Briggs
 

So, I guess that means the SM's don't have a fuel dip stick like the SN's? We SN's don't even sip electricity for reading the fuel level and it ALWAYS works !! 
Cheers, Craig SN68


---In amelyachtowners@..., <peacock8491@...> wrote :

We are leaving St Augustine for a month, and I am trying to get my electric usage to near zero......

 I then noticed that the fuel gauge still works.........

Any idea where the fuel gauge gets its power from?.................

Thanks as always to all in this group.

Tom Peacock
Aletes SM 240
St Augustine Florida

sbmesasailor
 

Tom,

If your bilge pump does kick on for any reason, what do you have to recharge your batteries?  If you don't have solar panels, you might want to consider installing one to provide a daily trickle charge, then you don't have to worry too much about a zero drain.

Dennis Johns
Libertad
Maramu 121

Gary Wells
 

I did put a spst switch at the fuel gauge to eliminate that draw. As well, I have made the "permanent" converters (24v/12v) switchable.
I had one other mystery draw and that was high-water alarm/bilge pump switch which had an electronic sensor and drew a small current all the time.

At the start of my quest I had about 0.38a draw but it's a zero now when everything is shut down.

If you have any fixtures that have USB charging ports, they will draw a little with their converters as well. 

Finally (I had to chase a 12v leak as well) if there is any build up of calcium or other corrosion on connectors to pumps or other hardware that might be a way for tiny amperage leaks to find a way to ground. 

Gary W.
s/v Adagio, SM 209
Gran Canaria

Jim Anderson
 

Mark, Thanks you for the correction. My math was for 12V rather than 24. So hopefully the following is correct:


If your SM is equipped with 8  12V, 110Ah batteries and you are drawing 0.1 Amps continuously at 24V then theoretically it would take 73 days, 8 hours to run your batteries down to 60% charged.

 

If you were drawing 0.2A at 24V then it would be half of that, 36 days, 16 hours hours.

 

For the 12 battery  "comfort pak" model it would be 110 days and 55 days, respectively.

 

8 X 110 = 880 Total Ah at 12V

880/2 = 440Ah at 24V

440 X 40% =  176 Usable Ah

176/0.1 = 1760 hours available at 0.1A draw

1760/24 = 73.33 Days

 

Hope that helps, or is at least mildly interesting trivia,

 

Jim

SM384 Sirena Azul