Battery discharge. ...normal?

jlh3rd

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I've read this entire thread.
My thoughts are......you've been informed from previous posters you have a problem. Disconnects and on/off switches provide a work around for the problem.
Sorry, the dealer's comment is bogus....and "standard" for dealers who don't give a crap....you said you're not impressed.
I have 4 cars, a motorcycle, and a boat. I never hear "clicks" when I re-connect a battery. If I did, in addition to a discharge problem, I'd be looking for the reason. Also, one car and my truck can sit for weeks with no startup issues. It was the same with my boat for a few years. ( battery dis-connect installed now)
Something is on that shouldn't be.
In a car, and it's time consuming, you can pull individual fuses to try and isolate the circuit with the problem.
I don't know what your boat has....but if you can do that and the click goes away, that might be the circuit causing the issue....

food for thought.....I don't think most new boats come with battery disconnects, do they?....
If you hook up a multimeter with that harness I posted and remove fuses one at a time....when you find the one here the draw drops down to like 30-50 milliamps then you have found the module thats staying on. Basically a simple process you can do it yourself....
yep....
 

harringtondav

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If you hook up a multimeter with that harness I posted and remove fuses one at a time....when you find the one here the draw drops down to like 30-50 milliamps then you have found the module thats staying on. Basically a simple process you can do it yourself....
Thanks. The boat is in winter storage. ...first thing when I pull it out.
 

tpenfield

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Thanks. The boat is in winter storage. ...first thing when I pull it out.
Boats do seem to take a year or 2 to get things 'dialed in'. Perhaps the excessive current draw is just one of those things . . . or you will find the culprit device that is stealing all of your electrons.
 

dingbat

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Thanks. I did the math and figured something is wrong.
Assuming my 1000 CCA battery is good (not verified), and depletes w/in 14 days, there is an approx 3A/hr draw with the main battery switch open. Not enough to cause a melt down, but not what I'd call "normal".
I'll call Regal. Not hopeful. All of their surveys direct me back to my dealer with any concerns. If I manage to get to a knowledgeable person I'll ask if this is normal. If so, I'll let them define the current.
Have you ruled out the bilge pump as being the culprit?

Bilge pump circuits are typically always energized and are notorious for current leaks through the windings. I'll had 2 bilge pumps exhibit such behavior (fail) over the years.

You also have "smart" bilge pumps that consume energy during normal "sensing" operation.
 

Lou C

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Good point, if you use a meter to measure draw it would be interesting to see what it is, with the switch off, then if it is elevated, pull the fuse for the bilge pump first. If it drops to a normal level you found your culprit.
 

harringtondav

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Have you ruled out the bilge pump as being the culprit?

Bilge pump circuits are typically always energized and are notorious for current leaks through the windings. I'll had 2 bilge pumps exhibit such behavior (fail) over the years.

You also have "smart" bilge pumps that consume energy during normal "sensing" operation.
I think I have an auto bilge pump. ...separate sensor from the pump. So this could be another suspect. The sensor wasn't as large as a float switch, so it could be as you mention.
My quarter turn main battery disconnect has four cables/wires attached to it. Two heavy gage entering from aft, and two small cables attached to the front. I'll try to get a wiring diagram from Regal. I suspect these two cables feed the "always on" stuff.
 

harringtondav

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Good point, if you use a meter to measure draw it would be interesting to see what it is, with the switch off, then if it is elevated, pull the fuse for the bilge pump first. If it drops to a normal level you found your culprit.
I checked amp draw between the B- post and cable before storage. I can't remember the meter's current limit, but it seemed to be over that limit flashing '333'. I was in a hurry and just satisfied that I saw some draw.
...something else for next spring.
 

harringtondav

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I contacted Regal service. He didn't know the amount of standby voltage draw, but sent me a copy of a service bulletin about the Fusion radio malfunctioning during main power disconnect. He said this issue had been associated to excess voltage draw. Easy fix if I can get the dealer to do it. ....dealer never mentioned this SB.
I checked Garmin's specs on the radio. 200mA standby, 700mA mute, 2A on. I've never heard the radio come on, but it's a modern touch screen setup that I'm still learning.
Regal also mentioned the bilge sensor is the only other suspect. I wrote back asking for the OEM p/n so I can do more research.
Does anyone know an electronic bilge sensor p/n, or standby draw? I recon it is small and probably the same across manufacturers.
 

dingbat

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I contacted Regal service. He didn't know the amount of standby voltage draw, but sent me a copy of a service bulletin about the Fusion radio malfunctioning during main power disconnect. He said this issue had been associated to excess voltage draw. Easy fix if I can get the dealer to do it. ....dealer never mentioned this SB.
I checked Garmin's specs on the radio. 200mA standby, 700mA mute, 2A on. I've never heard the radio come on, but it's a modern touch screen setup that I'm still learning.
Regal also mentioned the bilge sensor is the only other suspect. I wrote back asking for the OEM p/n so I can do more research.
Does anyone know an electronic bilge sensor p/n, or standby draw? I recon it is small and probably the same across manufacturers.
Looks like the Rule 1100 sense pump is 0.25A per day.

Glad mine is a good, old fashioned float switch
 

Lou C

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Well at least you have a few possible explanations there, I'd get them to follow up on the radio issue, I know that can be a problem sometimes with after market radios in vehicles because they sometimes quit going "to sleep" like they should and raw power continuously. Do you have a gas fume vapor detector, these are good to have, but I guess depending how they are wired they could draw enough to cause a problem over time. I have one myself but it is wired to the ignition on circuit so it is not drawing power when the ignition is off. I still have an old fashioned Sure Bail bilge switch, these only turn on when there's enough water in the bilge. I think the only thing that should get powered when the battery switch is off is the auto bilge circuit.
 

harringtondav

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Looks like the Rule 1100 sense pump is 0.25A per day.

Glad mine is a good, old fashioned float switch
Thanks. My sensor is a separate, small device wired to the pump. But .25A/day (10mA) is probably in the ball park. Per above I'm seeing 3A constant draw to drain a 1000A battery in 14 days. I'll measure actual draw from the radio and bilge sensor once the boat is out of storage.
 

harringtondav

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Do you have a gas fume vapor detector, these are good to have, but I guess depending how they are wired they could draw enough to cause a problem over time.
No. Seems I'm down to the radio and bilge system.
 

dingbat

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Per above I'm seeing 3A constant draw to drain a 1000A battery in 14 days.
Something isn't right.
3AH x 24 hours x 14 days = 1,008AH capacity?
3AH (125mA) per day x 14 days = 42AH capacity?
To put this into perspective.......my Grp. 27 Deep Cycle are 110 AH

What is the AH or RC rating of the battery in question?

Bear in mind the AH and RC ratings are based on draining the battery down to 10.5 VDC.
Do that a few times with a starting battery and you'll need a new one in no time
 
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harringtondav

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Something isn't right.
3AH x 24 hours x 14 days = 1,008AH capacity?
3AH (125mA) per day x 14 days = 42AH capacity?
To put this into perspective.......my Grp. 27 Deep Cycle are 110 AH

What is the AH or RC rating of the battery in question?

Bear in mind the AH and RC ratings are based on draining the battery down to 10.5 VDC.
Do that a few times with a starting battery and you'll need a new one in no time
Oops, my bad. Battery is a Continental Grp 21 1000 Marine/RV ....not 1000CCA.
800CCA, 140RC. The battery is dead w/in 14 days, well past 10.5 V. The VP instruments don't even wake up and beep.
So using my logic of total amp capacity of 800/(14x24)=2.4A constant draw. Not as large as I'd previously guesstimated, but still too steep for these two devices on standby.
The battery tried to start the engine once, but flat lined at least three other times, so it's likely compromised.....unless "Marine" gives me some grace.
 

dingbat

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Oops, my bad. Battery is a Continental Grp 21 1000 Marine/RV ....not 1000CCA.
800CCA, 140RC.
800 CCA is a meaningless measure of power for this discussion.

The number your concerned about is the batteries Reserve Capacity.

RC is the time in minutes that the battery can sustain a 25 amp load and remain above 10.5V.

140 Reserve Capacity = 140 Min. - (140/60)*25 = 2.333*25 = ~58Ah

So using my logic of total amp capacity of 800/(14x24)=2.4A constant draw.
Total AH capacity 58/336 hours = 0.173AH constant draw
 

harringtondav

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800 CCA is a meaningless measure of power for this discussion.

The number your concerned about is the batteries Reserve Capacity.

RC is the time in minutes that the battery can sustain a 25 amp load and remain above 10.5V.

140 Reserve Capacity = 140 Min. - (140/60)*25 = 2.333*25 = ~58Ah


Total AH capacity 58/336 hours = 0.173AH constant draw
Am I missing something when I say the battery has additional reserve below 10.5V? That remaining 10.5V is feeding the 'always on' circuits until it depletes to a dead battery.
 

tpenfield

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Am I missing something when I say the battery has additional reserve below 10.5V? That remaining 10.5V is feeding the 'always on' circuits until it depletes to a dead battery.
Not a battery 'expert' by any means, but depletion of the battery below the 'reserve capacity' level (10.5 volts) tends to do permanent damage to the battery.

I know from experience when I left my truck off of the battery minder for the winter. The battery had only a few volts left and would not re-charge. $200 later, problem solved 🤪
 

dingbat

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Am I missing something when I say the battery has additional reserve below 10.5V? That remaining 10.5V is feeding the 'always on' circuits until it depletes to a dead battery.
What you’re missing is that a 12V flooded, lead acid battery is technically “dead” at 12.0 volts.

At 10.5 V your down to 1.75V per cell and at risk of permanently damaging the battery.

Some good information here on Depth of Discharge and battery longevity
 

harringtondav

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What you’re missing is that a 12V flooded, lead acid battery is technically “dead” at 12.0 volts.

At 10.5 V your down to 1.75V per cell and at risk of permanently damaging the battery.

Some good information here on Depth of Discharge and battery longevity
I'm not discharging the battery intentionally, just trying to estimate the amount of the draw and sources of the excess load. That's why I'm using total capacity in that estimate. I'll have actual meter measurements in the spring by disconnecting devices. Assuming linear discharge rate my estimate is 2.4aH. The chart below tells me that's probably off, but close.
No doubt my battery has been compromised. I hope to get warranty on the bad devices. I'll feel extra lucky if the dealer replaces the resulting bad battery.

1668198402335.jpeg
 

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