Battery trouble

[Lance Jones]

Woke up and the bilge pump had been running all night as the sink foot pump had failed. When turning off through hull, I noticed the battery compartment was warm. When I opened it up, the #1 battery was very warm, #2 was slightly warm & #3 was normal. Could that be caused by the pump running all night; or, do I have another problem? Battery is now disconnected.

They are 79ah AGM purchased in 2005.

[Lance Jones]

With #1 removed and panel switch to both - no power. When switched to 2 at panel (Using starting battery) still no power. If I isolate the house bank by switching to 2, shouldn't I get power?

[Ken Juul]

Lance,
Need more info of how your set up, a diagram if possible. 

What are the battery voltages?

The batteries are 6 years old, could be near the end of their lifetime, but before pronouncing them dead need the above.

[Lance Jones]

Thanks Ken,
This is my weak point - 'lectricity!!!!! I have no clue as to how they are wired. However, #1 was at 12.8 when I pulled it out and put it on the dock to cool down. Other than the bilge pump running most of the night, nothing has changed in my wiring that would cause the battery to get hot.

I do know that i have a 1-b-2 switch on the panel and an On/Off switch on the settee outside the battery bank. 3 on the #1 bank (House) and 1 on the #2 bank (Starter)

[Lance Jones]

Btry 1  12.58
Btry 2  13 .0
Btry 3  13.01

[Ken Juul]

Ok from the info given, here is my SWAG (scientific wild a** GUESS)

Batteries 1, 2, & 3, the house bank, are wired in parallel to give you 12v, 237 amp hours, and are attached to post 1.  

Starting battery 4, is wired directly to the starter from it's own off/on switch.  It is not connected to post 2.  

You are at the dock, so I assume you had shore power all night, the shorepower should have powered the bilge pump thru the battery charger.  This is sort of verified by the battery being at 12.8 volts, if it had powered the pump all night it should be much lower.

I think the leak was just a coincidence.  With the age of the batteries, I would guess that 1 and 2 are starting to fail, 1 being in worse condition.  12v batteries are really 6 2v batteriy (cells) wired in series in a case.  One or more of the 2v batteries failing will make the charger work harder to keep the voltage up causing the case to heat up. The only way to be sure is to take all three of them to a battery shop and have them tested.  If any are bad, replace all three.  If none are bad, the next paragraph applies.

Surely somebody in Flt 13 understands 12v systems.  You need to get them on your boat and let them explain how your system is set up so that you understand it enough that you can draw a simple electrical diagram to help with this and any future problems.

Based on those voltages, the charger was working.  And it adds ammunition to the failing battery theory.

[Lance Jones]

Thanks a zillion Ken. I appreciate your help.

[Stu Jackson]

I agree with Ken's assessment.  Get some help to figure out what you have.  Sounds like old, dead batteries.

[Ron Hill]

Lance : I agree that your batteries are old and at the end of their life.

Please enlighten us as to what the electric bilge pump has to do with the failed manual foot pump????

You need to get a friend to help you diagram what your 12V DC electrical system looks like.  Also diagram your 110V AC system is, especially the shore power charger.  A thought

[Lance Jones]

Thanks Stu. That's what I was hoping was the issue. However, replacing AGMs is going to be 'spensive!

Ron, the foot pump failed last night while we were asleep and was flooding the bilge. So, the pump was keeping well ahead of the rising water. Usually we don't use it and the through hull is closed; but, it would appear that I failed to close it last time -- or one of the dogs was using it while we were at work. They have that oppossable thumb issue and can't close things like we can...

The folks on this site are amazing. I can't say how much I appreciate all of you!

[Stu Jackson]

Lance, there is really little reason to use AGMs in your environment, or for most recreational boaters for that matter.  Maine Sail discussed it in his "Darn AGM" topic, here:  http://forums.catalina.sailboatowners.com/showthread.php?p=848465&highlight=dual%20circuit

Save yourself a lot of money and actually consider getting better performance with simple wet cells.

We just LOVE to save YOUR $$$!!!  Don't worry, we'll find some other way to spend it for ya!

[Lance Jones]

Stu,
Good article. RTFM. Good one....

[Kyle Ewing]

Lance--I'd like to hear more about the sink foot pump failure.  What happened?  Is it something that could have been prevented with maintenance/rebuild?

[Albreen]

Lance - continuing with Kyle's question - did the discharge line from the pump to the sink drain line leading to the thru hull have a loop up under the counter and an anti-siphon valve? I think the C34 owners manual shows it is required to prevent siphoning if there is a failure of the pump. The PO in my boat had cut this out and routed the line directly into the sink drain and caused some minor flooding for me when this same thing happened about two seasons ago to my pump. But, in that case, we ended up flooding the bottom of the ice chest and at first couldn't figure out why. Needless to say, I put it back together and all is now well.

[Lance Jones]

I had been noticing that the bilge pump had been cycling on/off over the past couple of days. Couldn't find where the water was getting in. The other night, we got hit with a big wake and the cutting board fell over and had logged itself on top of the pump foot. No biggie as it just tipped over on it side. (All happened at night while we were asleep) When we woke up the next morning, water was coming out of the joint where the pump foot joins the pump housing. The hoses were fine and all the water was coming out of that joint. Will tackel that project this weekend after I replace my batteries.

Again thanks for all the help folks!