Battery alarm while moored. - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Electrical Systems
 Not a Member? 
  #1  
Old 07-25-2012
Junior Member
 
Join Date: Jun 2012
Location: NE Ohio
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jklingenstein is on a distinguished road
Battery alarm while moored.

2008 Beneteau 37'
Two batteries - Cranking and deep cycle
Battery age - <1 year

While on a ball recently our low voltage alarm went off in the middle of the night at 10.8V

All systems were off - main breaker was off - fridge was off - nothing was on. Started engine to charge for 30 minutes - All good

Three hours later.....same thing.

Ground problem ?
Suggestions on a troubleshooting starting point ?

Last edited by jklingenstein; 07-25-2012 at 08:57 AM.
Reply With Quote Share with Facebook
  #2  
Old 07-25-2012
asdf38's Avatar
Senior Member
 
Join Date: Jul 2010
Posts: 675
Thanks: 1
Thanked 4 Times in 4 Posts
Rep Power: 5
asdf38 is on a distinguished road
Battery alarm while moored.

Time to pull out the multimeter and check it. First, the obvious, what's the actual voltage of the batteries. Then measure the voltage at the meter and see what it's seeing. There are only a few possibilities, either the voltage was actually low, the wiring is flaky, the meter is on a point where there is a voltage drop (inadequate wiring/large load), or the meter is bad or programmed wrong. Another thought is electrical noise, are your sense leads too long and going past something "noisy" the fridge motor, a transmitter etc?

Ground is one of two wires, it's no more likely to be the black/yellow one than the red one..
__________________
1979 Contessa 26
Boston, Ma
Reply With Quote Share with Facebook
  #3  
Old 07-25-2012
Junior Member
 
Join Date: Jun 2012
Location: NE Ohio
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jklingenstein is on a distinguished road
Re: Battery alarm while moored.

We've never had this occur in the last three years.

Wouldn't there need to be a voltage drain somewhere for the battery to discharge without anything drawing current?
Reply With Quote Share with Facebook
  #4  
Old 07-25-2012
aeventyr60's Avatar
Junior Member
 
Join Date: Jun 2011
Location: Andaman Sea
Posts: 1,468
Thanks: 5
Thanked 21 Times in 21 Posts
Rep Power: 4
aeventyr60 is on a distinguished road
Re: Battery alarm while moored.

How easy did the motor start at 10.8 volts? Perhaps your meter and or the sensor has a short/resistence etc?
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



"Your dreams minus your doubts equals your net worth"

Life is a short journey, filled with emptiness and pain. Get all the sailing and booty you can.
Reply With Quote Share with Facebook
  #5  
Old 07-25-2012
Junior Member
 
Join Date: Jun 2012
Location: NE Ohio
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jklingenstein is on a distinguished road
Re: Battery alarm while moored.

Quote:
Originally Posted by aeventyr60 View Post
How easy did the motor start at 10.8 volts? Perhaps your meter and or the sensor has a short/resistence etc?
I believe the alarm monitors the house battery (deep cycle)

The motor started without a problem (cranking battery)
Reply With Quote Share with Facebook
  #6  
Old 07-25-2012
asdf38's Avatar
Senior Member
 
Join Date: Jul 2010
Posts: 675
Thanks: 1
Thanked 4 Times in 4 Posts
Rep Power: 5
asdf38 is on a distinguished road
Quote:
Originally Posted by jklingenstein View Post
We've never had this occur in the last three years.

Wouldn't there need to be a voltage drain somewhere for the battery to discharge without anything drawing current?
I took from your first post that you thought it was an issue with the meter (perhaps incorrectly). If your batteries are actually discharged then you either have a dying house bank, or yes, you have a load on your batteries that your not accounting for. I'd guess you have a bad bank, or you're just not accounting for something that's on (fridge door open?). It would be very unusual to find a device malfunction or wiring issue that didn't just result in a short and blow a fuse.
__________________
1979 Contessa 26
Boston, Ma

Last edited by asdf38; 07-25-2012 at 02:22 PM.
Reply With Quote Share with Facebook
  #7  
Old 07-25-2012
Junior Member
 
Join Date: Jun 2012
Location: NE Ohio
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jklingenstein is on a distinguished road
Re: Battery alarm while moored.

All panel breakers were OFF.... including the fridge breaker.

Nothing on the boat had electricity yet the battery voltage dropped enough to cause the voltage alarm to sound.
Reply With Quote Share with Facebook
  #8  
Old 07-25-2012
Senior Member
 
Join Date: Jul 2011
Location: marylands eastern shore
Posts: 126
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 4
bandaidmd is on a distinguished road
Sounds like your house battery has expired. Drag it out and give it a good charge than stop by autozone and have it tested
Reply With Quote Share with Facebook
  #9  
Old 07-25-2012
Classic30's Avatar
Once known as Hartley18
 
Join Date: Aug 2007
Location: Melbourne, Australia
Posts: 4,436
Thanks: 25
Thanked 35 Times in 35 Posts
Rep Power: 8
Classic30 will become famous soon enough Classic30 will become famous soon enough
Re: Battery alarm while moored.

Quote:
Originally Posted by jklingenstein View Post
All panel breakers were OFF.... including the fridge breaker.

Nothing on the boat had electricity yet the battery voltage dropped enough to cause the voltage alarm to sound.
Often essential equipment, like bilge pumps, will be wired directly to the house battery bank - not via the breaker panel.

It could be that the house battery is on it's last legs and the bilge pump is telling you.

Like others have already suggested, you'll need to get out a multimeter and find out. Good luck!
__________________
-
"Honestly, I don't know why seamen persist in getting wrecked in some of the outlandish places they do, when they can do it in a nice place like Fiji." -- John Caldwell, "Desperate Voyage"

Last edited by Classic30; 07-25-2012 at 08:57 PM.
Reply With Quote Share with Facebook
  #10  
Old 07-25-2012
Senior Member
 
Join Date: Feb 2008
Location: N. VA
Posts: 656
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 7
dacap06 is on a distinguished road
Send a message via Yahoo to dacap06
Re: Battery alarm while moored.

Quote:
Originally Posted by jklingenstein View Post
We've never had this occur in the last three years.

Wouldn't there need to be a voltage drain somewhere for the battery to discharge without anything drawing current?
No, not a voltage drain, a current drain. Current is flowing charge, so it means the current drain is discharging the battery. This old EE says the following:

1) I agree with the others - you need to dig out your VOM, set it to measure voltage, and see what (a) the voltage is at your battery when the alarm goes off, and (b) what the voltage is at alarm when it goes off. There are a number of likely possibilities (and a grunch of less likely possibilities). I'll talk about how to find the likely ones. You are likely to find one of these possibilities:

a. Your battery is actually well charged, voltage at the battery is OK, and you get the same voltage at your alarm. The alarm is not going off a the right voltage -- adjust or replace the alarm.

b. Voltage at the battery is OK but voltage at the alarm is different and lower. Look for poor connections from the battery to the alarm, or bad or inadequate wiring.

c. Voltage at the battery is actually low, and you read the same voltage at your alarm. It could be bad wiring, or it could be a bad battery. You need to perform one more test to tell which it is. So ...

Set your VOM to measure current instead of voltage, range up to 5 amps. Turn everything off as you had it before when the alarm went off. Remove the hot lead (+) from the battery and connect it to the black lead of your VOM. Attach the red lead of your VOM to the hot lead of your battery. Read the current flow. If it reads zero, keep switching the range down until you read microamps (which probably isn't accurate, so if it is zero or a few microamps, consider it to be zero).

c.1 -- if the current reads zero or nearly so, then you have a bad battery. Replace it. Have a battery place test it first, if you like.

c.2 -- if you read non zero current, then you have a high resistance ground. That could be a bad semiconductor in some electronic gear, it could be a corroded wire where the insulation has also failed and it touches a ground. It could be a poor connection to something, It could be a bad circuit breaker or switch, It could be anything wired directly to the battery, such as your bilge pump. It could be something you left on or plugged in inadvertently.

If c.2 is your answer, you will have to do some fault isolation. Start unplugging stuff one thing at a time until the current drops to zero or nearly so. If that doesn't work for you, start disconnecting circuits one at a time from your battery or the power distribution panel until the current drops.

Personally, I'd start with the bilge pump, especially if it has an electronic water level sensor. Both the pump and the wiring sit in grungy water, an environment that is fairly hostile to electronics.

Regards,

Tom
__________________
T. P. Donnelly
S/V Tranquility Base
1984 Islander 30 Bahama
Pasadena, MD

Last edited by dacap06; 07-28-2012 at 12:54 PM.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
repair rudder while moored batshaven SailNet FAQ 8 05-08-2012 10:58 AM
Moored WanderingStar General Discussion (sailing related) 10 04-27-2012 10:08 PM
Moored WanderingStar General Discussion (sailing related) 0 04-26-2012 02:37 PM
mast falling over on a moored hobie cat doghouseman General Discussion (sailing related) 16 06-24-2009 05:50 PM
Recommednation for moored daysailor in Maine jpeurach Boat Review and Purchase Forum 5 03-10-2006 11:09 AM


All times are GMT -4. The time now is 06:14 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.