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Capt Blithe
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Discussion Starter #1
Newish to me boat: My Xantrex LinkLite generally reads minus ~3.8 amps with everything off on the 12v side. I've never actually believed that it was a negative drain, preferring to think that it was just incorrect, and on shore power I'd gotten lazy about checking it out.

Yesterday, turned the refrig and battery charger off for a bit and I re-hooked up the AirX (400) after a bearing job, and watched the amp readout while listening to the AirX. As windspeed increased to maybe 10mph I watched the amp gauge on the batt monitor "fall" from -3.8 or 9 to -.8 amps. It never quite got to a positive reading before the wind died off.

Turned the AirX off, and the batt charger on, and amps jumped up to 26.5. Turned AB frig back on and watched amps drop down to 21 something ...

I now think the battery monitor is in fact working just fine and I really do have a current drain issue.

How do I get started finding the drain/short of almost 4 amps with everything apparently off?

Sys info:

Bank 1 = (4) 6v flooded batts, new last Oct ... terminals squeaky clean/tight
Bank 2 = (1) 12 v start flooded batt
AirX 400
Balmar 50/100 alt
RM wheel pilot
VHF
Laptop
12v am/fm radio


AB refrig draws about 4-5 amps but I can certainly hear it when running which is many times an hour for maybe 5 min at a time. PO mentioned that the AirX would not keep up with the frig at anchor.

Anything a common problem/good place to start? Thanks.
 

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Disconnect individual items one at a time.
 

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When you say "everything off" do you mean every device turned off or is the master DC circuit breaker off? The load should go to 0 when that is turned off (if the Xantrex power supply isn't on the main circuit). Do you have a clamp-type ammeter, which makes it easier to diagnose the source of the drain?

3.8A is a lot of drain - feel the heat around your Danfoss fridge compressor to get an idea of the amount of "work" that amperage does. Something is going to be warm on your boat, somewhere.

If you turn everything off, measure the voltage on the bank, then go away for a couple of hours and measure the voltage again what do you see - if the voltage has actually gone down then you do have a drain, if the voltage is the same (or higher, due to "resting" batteries after use) then your Xantrex reading might be suspect.
 

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Capt Blithe
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Discussion Starter #4 (Edited)
When you say "everything off" do you mean every device turned off or is the master DC circuit breaker off? The load should go to 0 when that is turned off (if the Xantrex power supply isn't on the main circuit).

Everything off meant all 12v circuit breakers off. Bilge pump isn't on panel but bilge is bone dry at the moment ... Xantrax reads -4.2. Turning the big red master switch off, Xantrex reads -0.1 wavering to -0.0.

Do you have a clamp-type ammeter, which makes it easier to diagnose the source of the drain?

... No but I don't mind getting the right stuff. Current one is Sperry DM-350A, and in use several years with now new battery.
An interesting day. Wish I could say I found the prob but no ...

I interpret the return to zero with red master switch off as the current drain is not associated with the 12 panel wiring/breakers. The only item not powered by the panel is the bilge pump but it's not running and is cold. Neither the AirX nor the Balmar are likewise on the panel, and the engine is not running.

I physically unscrewed the positive wire of each 12v circuit breaker. The negs are all tied into a bar. Nothing changed. I'm thinking all breakers are fine. I then touched all the 12 v elec items onboard ... only the frig compressor was warm.

About then my elec guy showed up to finish moving some switches around. ... Wait for it ... The elec guy added a length of 6 gauge wire to the AirX toggle and managed to have not one but two big shorts with fire and smoke.
This is precisely why I had someone else do the job; I don't need anyone's help to screw things up.

Needless to add he took the AirX out. There is a possibility the 50 amp fuse is blown. It looks ok but rattles. I doubt it's supposed to rattle but I too bummed to mess with it. It's Miller Time. I'm going to see if I can run 12 v thru it but if so, the $220 circuit board is fried. The "elec" guy promised to reimburse me for the circuit board. I smiled and nodded knowing that ain't ever happening.

So a potential whopper net loss for the day and no joy in the current drain.:(
 

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the pointy end is the bow
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I had the exact same problem with one of our previous boats. My recollection is that there was an additional grounding wire in the system that bypassed the shunt for the battery monitor. Even though both my banks were charged, the battery monitor showed that one bank was losing a lot of amps because of the current flow between the two battery banks. Drove me nuts for a while. Once I finally got there (nuts), I quit worrying about it ;)
 

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are you taking into account your bilge pumps and the panel itself??? those draw even when asleep.
The panel should not use power unless an indicator light is on - which would mean a circuit is turned on.
 

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Capt Blithe
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46 Posts
Discussion Starter #9
I had the exact same problem with one of our previous boats. My recollection is that there was an additional grounding wire in the system that bypassed the shunt for the battery monitor. Even though both my banks were charged, the battery monitor showed that one bank was losing a lot of amps because of the current flow between the two battery banks. Drove me nuts for a while. Once I finally got there (nuts), I quit worrying about it ;)

Many thanks for this. It's early here and I haven't had any coffee yet but this sounds like a very promising lead... I am not beyond an elec pun. Seems like a case for having the clamp on ammeter. And I gather you're saying while the "drain" was real it wasn't causing an actual drain to the system as a whole.

I had hoped my starting bank was really and truly isolated from the house but we shall see by following Zanshin's suggestion of measuring and remeasuring the banks to see if there is a difference over a couple of hours

I ran into the elec guy yesterday afternoon and the meeting went downhill pretty fast but he expressed some surprise that the AirX toggle had two 6 ga Negs coming off it where the diagram shows just one. My project for the day is to see what is what about that and to lengthen the AirX cables, and correctly transitioning from 6 to 8 gauge (per factory specs) and mounting the toggle on the panel rather than down where it lives now. It's that ol' when ya want it done right ...

I knew I'd have to learn this stuff someday, and that day has dawned.

The (now) ex-elec guy claimed that the use of too large of wire contributed to his screwdriver hitting two terminals and providing the fireworks :eek:. I have to agree but only wish he'd mentioned the need for smaller gauge before we took the AirX out. I also pointed out that he's the local boatyard elec guru but a lowly worm of a boatowner (me) owned an insulated elec screwdriver set. As noted, though, I didn't think of that in time either.

On the good news front, a brief little squall blew through last night, and after a ($4.73) 50 amp fuse, the AirX's LED was working again so it seems likely the sacrificial fuse worked correctly, saving the system.:)
 

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Old enough to know better
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Many thanks for this. It's early here and I haven't had any coffee yet but this sounds like a very promising lead... I am not beyond an elec pun. Seems like a case for having the clamp on ammeter. And I gather you're saying while the "drain" was real it wasn't causing an actual drain to the system as a whole.

I had hoped my starting bank was really and truly isolated from the house but we shall see by following Zanshin's suggestion of measuring and remeasuring the banks to see if there is a difference over a couple of hours

I ran into the elec guy yesterday afternoon and the meeting went downhill pretty fast but he expressed some surprise that the AirX toggle had two 6 ga Negs coming off it where the diagram shows just one. My project for the day is to see what is what about that and to lengthen the AirX cables, and correctly transitioning from 6 to 8 gauge (per factory specs) and mounting the toggle on the panel rather than down where it lives now. It's that ol' when ya want it done right ...

I knew I'd have to learn this stuff someday, and that day has dawned.

The (now) ex-elec guy claimed that the use of too large of wire contributed to his screwdriver hitting two terminals and providing the fireworks :eek:. I have to agree but only wish he'd mentioned the need for smaller gauge before we took the AirX out. I also pointed out that he's the local boatyard elec guru but a lowly worm of a boatowner (me) owned an insulated elec screwdriver set. As noted, though, I didn't think of that in time either.

On the good news front, a brief little squall blew through last night, and after a ($4.73) 50 amp fuse, the AirX's LED was working again so it seems likely the sacrificial fuse worked correctly, saving the system.:)
Good that the fuse did it's thing! Rare on a boat that a less than $5 fix is in order! I believe you should offer sacrifice to the gods for that one!

I would be surprised that it could be too big cable, normally the bigger the better when carrying big voltage and if it has a 50 amp fuse then I would think 6 would be more appropriate, especially if you are going with a longer run.
 

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Old enough to know better
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Many thanks for this. It's early here and I haven't had any coffee yet but this sounds like a very promising lead... I am not beyond an elec pun. Seems like a case for having the clamp on ammeter. And I gather you're saying while the "drain" was real it wasn't causing an actual drain to the system as a whole.

I had hoped my starting bank was really and truly isolated from the house but we shall see by following Zanshin's suggestion of measuring and remeasuring the banks to see if there is a difference over a couple of hours

I ran into the elec guy yesterday afternoon and the meeting went downhill pretty fast but he expressed some surprise that the AirX toggle had two 6 ga Negs coming off it where the diagram shows just one. My project for the day is to see what is what about that and to lengthen the AirX cables, and correctly transitioning from 6 to 8 gauge (per factory specs) and mounting the toggle on the panel rather than down where it lives now. It's that ol' when ya want it done right ...

I knew I'd have to learn this stuff someday, and that day has dawned.

The (now) ex-elec guy claimed that the use of too large of wire contributed to his screwdriver hitting two terminals and providing the fireworks :eek:. I have to agree but only wish he'd mentioned the need for smaller gauge before we took the AirX out. I also pointed out that he's the local boatyard elec guru but a lowly worm of a boatowner (me) owned an insulated elec screwdriver set. As noted, though, I didn't think of that in time either.

On the good news front, a brief little squall blew through last night, and after a ($4.73) 50 amp fuse, the AirX's LED was working again so it seems likely the sacrificial fuse worked correctly, saving the system.:)
Good that the fuse did it's thing! Rare on a boat that a less than $5 fix is in order! I believe you should offer sacrifice to the gods for that one!

I would be surprised that it could be too big cable, normally the bigger the better when carrying big voltage and if it has a 50 amp fuse then I would think 6 would be more appropriate, especially if you are going with a longer run.
 

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Not hunkered over your system but is it possible the current draw is actually an IR drop across the internal bits of the either neither both switch? losing some here(variable with current) can cause a mystery.
 

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Capt Blithe
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46 Posts
Discussion Starter #13
Gotta think that thru Capt Len. Thanks.

Wasn't able to buy a clamp-on ammeter locally so a short delay (can't help myself being so punny). 4 amps is a lot. Something has to be hot. Starting to consider the Balmar smart regulator. It's much smarter than I am, I'm sure, and far more complicated. It's not on but it's not called electrickery for nothing.:)

Right on with the $5 fix. I am toasting the gods as we write.

I am not receiving email notices though I've checked the boxes in the User CP. Thoughts?
 

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Capt Blithe
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Discussion Starter #14
UPDATE: The current drain was from the house bank to the Balmar. What made that less obvious than you'd think was that the drain was thru the 3 way toggle controlling the Balmar alternator.

In position One, there was a .5 amp drain. In the center position I take to be Off, zero drain. Position 3 had the full monty 4.x something amp drain, and the alternator, in Position 3 only, was hot indeed without the engine running.

I'd like to say I deduced this because I'm a genius but I just kept sittting and staring and screwing with connections and switches til I had that "ah ha!" moment. Overall, it took several hours of trial and error, and it's easy for me to imagine paying a real tradesman $75 an hour to sit and stare so I ain't feeling all that bad right now and a toast to the gods is clearly due.

Not altogether sure of my next move but I suspect my house bank will be much the better for not losing 100 Ah per day. I hope the Balmar survived.
 

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Glad I found Sailnet
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Congratulations. I was going to suggest disconnecting all non-battery wires from your negative terminal shunt, to make sure you are getting a good zero reading. But you seemed to have solved it.

Regards,
Brad
 
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