How many amps are you leaking with nothing switched on?

[Wotname]

Just start off by checking the zero of the panel meter by disconnecting one of the battery bank terminals.

With the battery disconnected, you know there are zero amps flowing, now see what the panel meter is indicating. If it is not zero, you should find a small plastic screw near the bottom centre of the meter face which will allow you to set the needle to zero.

[senormechanico]

I believe his panel meter is digital.

Steve

[earthbm]

The panel meter is indeed digital (as Steve would know after sailing it 1200nm with me last year). When plugged into shore power (after being plugged for a week), the current says 2.0amps. When I was out sailing and had most but not all things off (no instruments, but with light on) the meter was reading 0.0amp. With instruments and autopilot the typical reading is -8.0amp. So it is as if the meter is showing a number that is ~2amps too positive. Or that the meter is accurate, the light draws near zero, and shore power continues to pump 2 Amps into the batteries even after one week.

I assume positive means current flowing into batteries, so it was probably wrong to characterize it as a leak.

[hellosailor]

Digital:
OK, but if it is LCD technology, the display takes flea power (technical term<G>) but the backlights can be 4xLED taking 20mA each, for .08A consumed, let's say 0.1A.

On the other hand if the display is LED, it can take 20mA per segment, four 8-segment numerals taking up to 1.6A is they're all light up with numbers that use lots of segments.

So there's some room there too.

Very easily, as you suggest, the shore power may be keeping a 2A charge up as a trickle charge and that wouldn't hurt a large bank. If you kill the shore charger, does that go away?

[Lancerbye]

Originally Posted by earthbm

The panel meter is indeed digital (as Steve would know after sailing it 1200nm with me last year). When plugged into shore power (after being plugged for a week), the current says 2.0amps. When I was out sailing and had most but not all things off (no instruments, but with light on) the meter was reading 0.0amp. With instruments and autopilot the typical reading is -8.0amp. So it is as if the meter is showing a number that is ~2amps too positive. Or that the meter is accurate, the light draws near zero, and shore power continues to pump 2 Amps into the batteries even after one week.

I assume positive means current flowing into batteries, so it was probably wrong to characterize it as a leak.

Congratulations! Your system is working as it should be and you have learned something about your DC system. The 2 amps is normal trickle charge being supplied by your charger. You have to love it when a plan comes together. ( A team)

[senormechanico]

Ivan,

When I was on the boat, I didn't see anything out of the ordinary re the meter reading.
The only real test here is to unplug the boat and make sure everything is turned off.
Switch off all panel switches, make sure the Spectra backlight is off etc.

BTW, it was 1250 miles, with a trip average of 8.5 knots.

Steve

[Nicholson58]

Originally Posted by daddle

How do you know? How is it measured?

Something IS "switched on". It probably is more normal than it should be only because of the typical terrible condition of boat electrical systems. I would find it just so you know what it is.

I figured finally that the Xantrex is runnin all of the time. Parasitic losses are at the Link 2000 to operate the processor and there is a big relay as part of the Pathmaker. The coil in this relay is often energized. I'm going for replacement with a solid state relay and/or a hard interupt switch to disable it. I might just put in an old fashioned battery selector.

[hellosailor]

Wotname-
Disconnecting a battery terminal, depending on how things were configured, where the shunt was installed, might just zero out everything. Or not.
And with zeroing out analog meters, be careful about that. I've seen a number that could be adjusted perfectly at either end of the scale, or at midscale, and that would make them perfectly accurate AT THAT POINT of the scale, but also totally inaccurate at the other points of the scale. Overall better not to adjust that unless you can actually test and recalibrate to ensure it is not just trading off one problem for another. The law of unintended consequences, right?

[Nicholson58]

I pull the two battery neutral cables at the shunt for the winter. With AGM, they discharge very little.

[earthbm]

Okay, it is the panel meter calibration after all (couldn't have been still trickle charging at 2 amps after one week, could it?). Simple -- switch off everything, unplug shore power, still +2 amps. Switch the light (and fridge) on = zero amps. Switch a few more lights on = -2 amps. The good news is that there is no evidence of leak. The bad news is that the amp draw I thought I had with instruments + autopilot is 10 amps, not 8.

Thanks for helping me think through this!