Magic DC

[sailorboy1]

Originally Posted by skipmac

Still got a reading. Smaller 0.2 mV but still showed a voltage potential.

Here's another question (or two). Don't you have an always on circuit directly to the battery and bypassing the panel for a bilge pump? Is that connected when you see the monitor come on? yes my bllge pump bypasses the main DC panel. But it was off as the negative cables on the batteries weren't on the batteries yet.

What about the battery charger? Is that operating when this happens? It wasn't on. The main AC supply breaker was open/off.

I know that I've seen this "problem" when both disconnecting and connecting the batteries. I don't know if shore power was physically plugged in every time (it probably was).

Maybe I'll try some experiments. Since the BM powers up and the display lights up it probably could light the LED ion the main DC breaker if I shut that. I could also setup the same conditions and pull the fuse on he little start battery solar power.

[Paul Elliott]

Does this BM power up even with the battery (+) disconnected? With all the wires that normally go to the (+) being connected together?

I'm telling you that the battery with the (-) completely disconnected has *nothing* to do with your problem, unless there is a stray path or overlooked connection. You are looking in the wrong place. Simplify your problem. Disconnect all possible power sources. This is not magic. When you figure this out it will, in retrospect, be ridiculously obvious.

[sailorboy1]

Originally Posted by Paul Elliott

Does this BM power up even with the battery (+) disconnected? With all the wires that normally go to the (+) being connected together?

Don't know which is why I said it may have something to do with the little start battery solar panel.

[Captain Bill]

You said you connected all of the positive terminals first. I assume that this includes the + lead from the solar panel. If the negative lead from the sol ar panel is attached to the negative bus you now have a complete circuit. I assume that normally you disconnect all of the positive connections but the solar panel from the battery for the winter, thus isolating your battery monitor so it is not seeing the power from the solar panel. When you connect all the + leads together at the battery it can now see the power from the solar panel. The solar panel does not require a battery in the circuit to produce power, just a current path from the + to the - leads.

[jeepbluetj]

What Captain Bill said.

Fun thread, too bad I was out sailing today.

Static electricity IS a full circuit. There's just a big capacitor in it.

And of course, you do need some sort of a circuit for current to flow. Nothing's magic.

[exMaggieDrum]

Originally Posted by boatpoker

ABYC requires the DC negative to be bonded to the AC ground,

I have studied electricity for years ( maybe one day I'll understand a little bit of it) and noticed recently that all of what we think of as known science in electrical matters is still noted as "theory" in serious scientific journals.

I've never noticed any journals which discuss basic electricity as "theory". In the scientific community when you describe something as a "law" it is considered a given "fact". E.g. Ohm's Law.

[uncle stinkybob]

I've never been afraid to ask a stupid question so.....if there were a piece of equipment wired in to the circuit that had an internal memory thus an internal battery, could it possible cause this?

[Paul Elliott]

Sailorboy1, did you ever figure this out? Don't keep us in suspense!

[sailorboy1]

Originally Posted by Paul Elliott

Sailorboy1, did you ever figure this out? Don't keep us in suspense!

No, have had more important things to work on. I do feel it is likely that it is the small solar panel for the start battery even though the battery isolator should prevent it from getting power (guess it leaks enough mA).