Catalina 34

General Activities => Main Message Board => Topic started by: Lance Jones on September 22, 2011, 04:39:44 AM

Title: Battery trouble
Post by: Lance Jones on September 22, 2011, 04:39:44 AM
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.
Title: Re: Battery trouble
Post by: Lance Jones on September 22, 2011, 06:42:39 AM
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?
Title: Re: Battery trouble
Post by: Ken Juul on September 22, 2011, 08:55:31 AM
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.


Title: Re: Battery trouble
Post by: Lance Jones on September 22, 2011, 09:00:31 AM
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)
Title: Re: Battery trouble
Post by: Lance Jones on September 22, 2011, 09:46:07 AM
Btry 1  12.58
Btry 2  13 .0
Btry 3  13.01
Title: Re: Battery trouble
Post by: Ken Juul on September 22, 2011, 09:52:50 AM
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.
Title: Re: Battery trouble
Post by: Lance Jones on September 22, 2011, 09:58:53 AM
Thanks a zillion Ken. I appreciate your help.
Title: Re: Battery trouble
Post by: Stu Jackson on September 22, 2011, 09:59:14 AM
I agree with Ken's assessment.  Get some help to figure out what you have.  Sounds like old, dead batteries.
Title: Re: Battery trouble
Post by: Ron Hill on September 22, 2011, 11:48:11 AM
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
Title: Re: Battery trouble
Post by: Lance Jones on September 22, 2011, 11:54:01 AM
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!
Title: Re: Battery trouble
Post by: Stu Jackson on September 22, 2011, 12:16:12 PM
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! :D
Title: Re: Battery trouble
Post by: Lance Jones on September 22, 2011, 01:27:20 PM
Stu,
Good article. RTFM. Good one.... :rolling
Title: Re: Battery trouble
Post by: Kyle Ewing on September 22, 2011, 11:50:31 PM
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?
Title: Re: Battery trouble
Post by: Albreen on September 23, 2011, 05:39:13 AM
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.
Title: Re: Battery trouble
Post by: Lance Jones on September 23, 2011, 08:08:47 AM
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!  :clap
Title: Re: Battery trouble
Post by: pablosgirl on September 23, 2011, 09:20:13 AM
Hi all,

Found this artical on deep cycle batteries that came from the solar charging / renewables industry While I was searching for 6volt battery replacements.  Explains the differences (pros and cons) in very easy to understand language that complements Mainsail's comments.
http://www.windsun.com/Batteries/Battery_FAQ.htm (http://www.windsun.com/Batteries/Battery_FAQ.htm)
Hope this will aid you in your decission on which battery to purchase.

Fair winds,
Pablo
Title: Re: Battery trouble
Post by: Lance Jones on September 23, 2011, 09:26:46 AM
Informative article Paul Thanks!
Title: Re: Battery trouble
Post by: Stu Jackson on September 23, 2011, 11:03:38 AM
In addition to my pm to you, there's also this:  http://www.c34.org/wiki/index.php?title=C34_Battery_Selection

Not much has changed, other than Maine Sail's excellent discussions about the serious downside of AGM batteries for general recreational use.  Those issues are covered in the "Electrical 101" topic.
Title: Re: Battery trouble
Post by: Ron Hill on September 23, 2011, 02:01:57 PM
Paul : The article site you posted is EXCELLANT !!  It's SO great because it covers the entire field of battery aspects!

It should be required reading for all boat owners.

I surely hope that this site in in our C34 WiKi.  


Added to the wiki, electrical then batteries.  Ken Juul
Title: Re: Battery trouble
Post by: Ralph Masters on September 23, 2011, 02:52:53 PM
Paul,
The read on the battery is excellent.  Answered several questions I had.  Covered very well all aspects of battery life and life with a battery.

Thanks for the post,

Ralph
Title: Re: Battery trouble
Post by: Lance Jones on September 24, 2011, 05:42:07 AM
Thanks all! Swapped batteries around yesterday and all are cool today. Woo-hoo!
Title: Re: Battery trouble
Post by: Ralph Masters on September 24, 2011, 11:34:30 AM
The one question I still have is how do they figure percent of discharge.  If I take 10 percent of 12.7, 1.27 that does not add up to what they show on the chart as 10 percent discharge.  Answers please.   :shock:

Ralph

Ken, I'm just a poor black shoe sailor, give me a break.
Title: Re: Battery trouble
Post by: Ron Hill on September 24, 2011, 02:59:57 PM
Ralph : The way I figure discharge is:
If I have a 400 amp hr house bank and I discharge it 10% I now have 360 amp hours remaining.

To me the only important % discharge number is to never go below 50%, so you get the best number of charge/discharge cycles out of your battery bank (and get the biggest bang for your $$). If you can go less than 50% discharge - all the better.

If you are referring to the chart in the WindSun site - each .05 volts represents approximately 5% of charge.   

The electrical Gurus may not agree, but that's the way I figure it!!   A few thoughts
Title: Re: Battery trouble
Post by: mainesail on September 24, 2011, 06:13:52 PM
Quote from: SD Diver on September 24, 2011, 11:34:30 AM
The one question I still have is how do they figure percent of discharge.  If I take 10 percent of 12.7, 1.27 that does not add up to what they show on the chart as 10 percent discharge.  Answers please.   :shock:

Ralph

Ken, I'm just a poor black shoe sailor, give me a break.

A number like 5% is measured in hundredths of a volt and a 10% drop is in the tenths of a volt range hence why using voltage to tell state of charge, even after the batteries have rested for 12-24 hours, is often a futile effort. Also the drops in voltage are not linear for each 10% drop..

These are Trojan's numbers for open circuit voltage readings for approximate state of charge.

100% = 12.73
90% = 12.62
80% = 12.50
70% = 12.37
60% = 12.24
50% = 12.10
40% = 11.96
30% = 11.81
20% = 11.66
10% = 11.51
Title: Re: Battery trouble
Post by: Ralph Masters on September 26, 2011, 10:29:48 AM
Ron, Mainesail,
Thank you for the information.

Ralph