How to track down a current drain

[Mickeyrouse]

I may be hoping something is working better than it does, so here goes:
It seems like I have a current drain. the reason I suspect this is a reading I get from my Xantrax Link 10. According to how I read the manual, the device will tell me how much current is being withdrawn from the system at any point in time.
So, with every circuit breaker on the breaker panel switched off, the Link 10 says The house batteries are being drawn down by 5.9 amps. The only exception is the Balmar Digital Duo Charge ( DDC.) I understand that it only kicks in when the house bank is “fully charged”, whatever that may be, and then to kick off when the engine start battery is also “fully charged.” But since the charge state for both battery banks is indicated as charged, it seems like the DDC is not the problem. Besides, turning the DDC off doesn’t effect the amp drain on the Link 10.
So, does the Link 10 tell me what I think it does? And if so, how do I go about tracking down my voltage drain?

[Jammer]

You have some choices. 6 amps is a lot and should be easy to find.



You can disconnect the duo charge and see whether the problem goes away. That is an easy first step.


You can use a clamp-on DC milliammeter to determine whether you're really losing six amps somewhere and to figure out where. I have this one: https://gtc.ca/product/cm100-milliamp-clamp-meter/ - expensive but has probably saved me a battery or two over the years, and handy to have.


Without a meter, you can pull breakers/fuses or otherwise disconnect stuff until your Link 10 shows zero.

[StuM]

Originally Posted by Jammer

...
You can use a clamp-on DC milliammeter to determine whether you're really losing six amps somewhere and to figure out where. I have this one: https://gtc.ca/product/cm100-milliamp-clamp-meter/ - expensive but has probably saved me a battery or two over the years, and handy to have.

Yep, a DC clampmeter is invaluable in resolving electrical issues like this one.
No need to spend hundreds of bucks on a meter unless you are a serious electrician. Even relatively cheap ones will tell you where current is flowing through wiring:
After someone blew up my good Fluke, I got a Digitec QM1632 Clamp Meter for under AUD100 and it does everything I need.

[goboatingnow]

Yes a DC clamp meter is very useful I have a Uni-T one from Amazon for €60.

[Mickeyrouse]

Originally Posted by Jammer

You can use a clamp-on DC milliammeter to determine whether you're really losing six amps somewhere and to figure out where. I have this one: https://gtc.ca/product/cm100-milliamp-clamp-meter/ - expensive but has probably saved me a battery or two over the years, and handy to .

I have thrown all circuit breakers off and switched the Duo Charge off, no change. I have not physically disconnected it. I have a Fluke clamp meter, but I don’t know exactly how to use it for this purpose. Where do I take tge reading(s)?

[flee27]

Make sure your meter does DC amperage with the clamp. Some only do AC voltage through the clamp.

I would start by clamping around the main positive wire from you house bank to verify you are pulling your 6 amps shown by the battery monitor. This will confirm what you battery monitor is telling you. If you battery monitor is correct, then start moving the meter around systematically to other feeds as the branch off from the main feed. Doing this you will narrow down the circuit that has the draw.

If the draw is actually present and turning off breakers/duo charge doesn't eliminate it. Then it must be something not running through your breakers. Something like a bow thruster, invertor or windlass. Not many circuits that you don't eliminate with the breakers. Or a bad connection/shorted wire before the panel.


Good luck. Let us know what you find.

Foster

[Mickeyrouse]

Thanks, that’s a plan. Windlass could be suspect- even though it has an independent switch, things could still amiss there. The Fluke clamp meter reads AC and DC.

[Jammer]

Originally Posted by flee27

I would start by clamping around the main positive wire from you house bank to verify you are pulling your 6 amps shown by the battery monitor. This will confirm what you battery monitor is telling you. If you battery monitor is correct, then start moving the meter around systematically to other feeds as the branch off from the main feed. Doing this you will narrow down the circuit that has the draw.

Yep.


DC clamp ammeters are susceptible to magnetic fields. Be sure it reads zero when it is near the wire you want to test but with nothing inside the jaws.

[bensolomon]

Check your bilge pumps. They sometimes are wired directly to the battery via a float switch.

[Stu Jackson]

How long have you had this boat? How long has this been going on? Have you done any re-wiring lately or has someone else for you?

[Mickeyrouse]

Originally Posted by bensolomon

Check your bilge pumps. They sometimes are wired directly to the battery via a float switch.

Not on this boat

[Mickeyrouse]

Originally Posted by Stu Jackson

How long have you had this boat? How long has this been going on? Have you done any re-wiring lately or has someone else for you?

Had this boat 26 years. Totally re-wired a few tears ago, no problems. No one else has touched it in this time.

[Madehn]

do you have an inverter--many of the older units have an idle current even when there is nothing plugged into the 110volt outlets. Newer models send a piulse down the line to detect a load- if a load is indicated then they turn the inverter on-- samll loads such as charging of cordless drills etc can trigger the inverter to stay on. Mine uses about 4.5 amps at idle.- it is older and i have now added a second inverter charger that has the pulse system.

[Nord Sal]

Did you calibrate the meter?

On my battery monitor, I disconnected the battery's negative cable so I know that no current is flowing through the shunt and zero the meter so that it reads 0 amps. This neglects the few milliamps (~ 3 mA for my unit) that the meter draws itself but is close enough.

[Rumrace]

I have a good friend many years Master Electrician and electronics. He has clamps headphones and other strange things. Yellow clamps red clamps. You need to call a guy like him.
6amp is a plotter, Fridge, heater, electric motor, your neighbour stealing power, it’s big.
One clue is folks think it’s okay to plug in house transformers in non switched outlets. Do you have 18 plugged in. A Flat Screen TV in instant on mode comes close add a transformer or two getting close.