Another battery question , ahem

Jun 24, 2014
80
Westsail 28 72 Long Beach , California
Recently I had a battery charger installed on our boat , the electrician and I started on with the operation and I forget why but I checked the voltage on the battery's . The house bank (open flood) was at float 13.2 and the starter batt. (sealed acid) was at 12.7 . The charger we were replacing was the sealed electronic multi stage type and was about 15 yrs. old . Normally that charger kept both batts. floating the same , 13.2 . I thought doesn't matter because we are installing a new charger , (house and starter are about 3 yrs . old) . Now it's the same starter will not charge higher than 12.7. My first thought is the starter batt. is on it's last legs ?
My electrical guy said open flood and sealed acid mix will be ok with the new charger , I don't really believe him . Is he wrong ?
And lastly how critical is the float voltage ? With my new charger it's programmable , I'm still learning to program it . On one setting it was floating 13.2 need 13.5 on another setting it was floating 13.8 .
Thanks , Mark .
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
When you say your starter is sealed acid I presume you mean "maintenance free" flooded lead acid. The other possibility is AGM. If it's just a sealed flooded lead acid then it's the same chemistry as your house bank, so it should be fine to use the same charge voltages. The voltages for AGM could be different.

The fact that your starter is staying at 12.7 makes me think it's just not charging at all. That is a standard resting voltage. If the battery were failing it would still charge at the voltage the charger tries to give it, unless it were really internally shorted, in which case it would be way under 12. What does your wiring look like? How is the charger connected to the two banks?
 
Jan 11, 2014
11,324
Sabre 362 113 Fair Haven, NY
What model charger? How is it wired to the 2 batteries? How old is the start battery?

Some chargers have multiple battery connections, but the output is the same on all connections.
 
Jun 24, 2014
80
Westsail 28 72 Long Beach , California
Hi David . yes the starter is a sealed lead acid maintenance free type . I'm thinking like you too 12.7 is 100% at rest , I did however run it down to 12.2 and it very slowly came back up 12.6 last night I will check it today . And weird thing there was never a charge voltage it was always under 12.7 . I have never seen this . Without going into a large explanation the charger is brand new it is wired correctly per ABYC standards , and looks beautiful . The thing that really has me wondering is that the old charger was doing the same thing so by my thinking it's a bad battery . But I have never seen a battery act like this .
dlochner , the charger in question is the Sterling Pro Charge red cap . 40 amp.
 

Bob J.

.
Apr 14, 2009
773
Sabre 28 NH
I know my charger cycles/times the float stage off after the battery is fully charged rather then stay in float continously. If your open circuit voltage is 12.7, sounds like the battery is at 100%. Maybe your charger does the same.
 
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Jun 24, 2014
80
Westsail 28 72 Long Beach , California
Hi Misfits , yes the charger is of the CEC compliant type I was running it in power supply mode witch bypasses CEC
 
Jun 24, 2014
80
Westsail 28 72 Long Beach , California
OK , I have some answers . First the battery was tested by a type of meter that I have never seen before and was found to be good . Long story short , loose connection on the 1-2- all- off rotary switch (I was not the last one to tighten the nut) . We changed the programming on the charger back to power supply from battery charger , so now I'm back on the CEC type charge . When it was in battery charger mode it was floating the house bank at 13.8 that was to much and it was only supposed to float at 13 . 6 and even that was a little high , so now back in CEC mode it charges at normal rates then goes to float for a while and when done shuts off and when the batt . gets below 12.7 it starts charging again and then goes to float at 13.6 . So I'm thinking this is exercising the batt. and that's a good thing . So after the guy went away I went back in the engine room and started looking at the rotary switch and checked connections . I put my wrench on the nut to tighten (holding the cables so it wouldn't just twist) nuts were tight but I could rock the cable and the threaded stud moved back and forth . so now I don't have a lot of confidence in the switch . At least that is something I can R&R . Some pictures , thanks for your guys reply's .

IMG_0243 by mark westi, on Flickr

IMG_0244 by mark westi, on Flickr
 
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Oct 24, 2010
2,405
Hunter 30 Everett, WA
Many times people throw parts at a boat before they property troubleshoot. Too bad because it costs money without fixing anything. Corrosion is the bane of boats and airplanes. If you had one bad connection (that you seem to have located) you should disconnect each connection and clean it. (I often lightly sandpaper it) then reassemble it and then use some dielectric to keep moisture out. I've had good success with Boeshield but there are others. Now it should last.

As for your loose selector switch, see if you can disassemble it and fix it. No reason to send it to a landfill if you can do a simple repair. It would be really unusual if it were actually worn out.

Ken
 
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Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
You seem to have a battery isolator, that black thing with three wires and heat fins. You should read up on them. We need more info on how your boat is wired, but that is a very good charger.
 
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Jan 11, 2014
11,324
Sabre 362 113 Fair Haven, NY
Now that you are under way solving the DC problem. You have a really serious AC problem. The metallic AC boxes are not a good idea due to corrosion. And, you should look inside of them to see if they used wire nuts, another poor idea. And, did the prior owner use marine grade tinned wire or solid strand copper, a very poor idea.

The black box with fins looks like a diode based battery combiner or isolator. This allows the batteries to be connected for charging from a single source and blocks them from discharging into each other. They work, but have a significant limitation, in that there is a limitation on the charging voltage, it will top out at about 13.8 v. Not enough for bulk charging. A better alternative is an ACR. See this article: https://marinehowto.com/automatic-charging-relays/

Are the cables going to the battery switch actually black? Or just exceptionally dirty? It is a little hard to see in the photo, but they almost appear as though they have been over heated and the insulation is charred. Also, take a look at this article on installing battery cable lugs. https://marinehowto.com/making-your-own-battery-cables/
 

DArcy

.
Feb 11, 2017
1,691
Islander Freeport 36 Ottawa
As for your loose selector switch, see if you can disassemble it and fix it. No reason to send it to a landfill if you can do a simple repair. It would be really unusual if it were actually worn out.
Battery selector switches don't last forever. Mine failed a few years ago and needed to be replaced. Probably similar vintage to @markwesti Westsail.
You have a really serious AC problem. The metallic AC boxes are not a good idea due to corrosion. And, you should look inside of them to see if they used wire nuts, another poor idea. And, did the prior owner use marine grade tinned wire or solid strand copper, a very poor idea.
My AC looked like that picture and it was the OEM back in the 70's that installed it. There weren't any wire nuts but it was solid copper Romex wire. Production boat builders didn't follow any marine standards back then. I replaced it all with marine stranded tinned copper wire and plastic boxes. Not very expensive or difficult to do on a small boat but a big improvement.
 
Jun 24, 2014
80
Westsail 28 72 Long Beach , California
Ken , actually I did trouble shoot this time before tossing . At first I was going to replace the batt. before doing anything but I called my gold plated electrician first and he saved me . As for the loose selector switch I never thought about repairing it wouldn't it be nice if I could just tighten it up , on the other hand that switch is 40 yrs. old
Stu , yes that is a battery isolator . It was installed on the boat , by my request when we first got the boat in the mid 90's .
Whoa ! Need more info on how the boat is wired ? That might take a while , first AC is stock factory from the late 70's there are outlets through out the boat and in the engine room . We did just re place the AC beaker switches on the main switch panel .
DC is also stock factory , however components (like the charger) have been added some tried and then removed , like a alternator by pass set up that was a total waste of money . Just recently I rewired the mast , I got rid of a lot of stuff and replaced with new . Stu is there something specific you want to know ?
dolchner I know I'm not a fan of these galvanized steel boxes either , fact is though they have been working fine from day one .
As for solid wire and wire nuts honestly I have never had the covers off to check so I don't know I agree they all need to be R&R .
In the past it has been suggested that I get rid of the Isolator by some and others have said to keep it . The way I understand it , it only effects the alternator and not the battery charger .
As far as cooked wires being left in place , come on give me a break well this the internet you don't know me .
Darcy , for sure builders varied some more than others . And I'm like you , that switch is old just get a new one .
 
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Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Stu , yes that is a battery isolator . It was installed on the boat , by my request when we first got the boat in the mid 90's .
Whoa ! Need more info on how the boat is wired ? That might take a while , first AC >>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
DC is also stock factory , however components (like the charger) have been added some tried and then removed , like a alternator by pass set up that was a total waste of money . >>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
Stu is there something specific you want to know ?
Mark, we were talking about the DC system, right? So I snipped out the AC.

Even in the 90s isolators were seen as voltage killing devices and were replaced with VSRs (voltage sensitive relays), be they combiners, oil pressure switches, Blue Sea ACRs and the like.

Your OP said you had voltage issues on your reserve/start bank. That means either a connection or a comopnent. You have a high quality new charger.

My basic question is how your AO (alternator output) is run. Does it go to the 1-2-B switch or to your house bank?

You may be interested in these links:
OEM 1-2-B Switch Wiring History http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

This is a newer primer for boat system wiring design with a thorough diagram: Building a Good Foundation (October 2016)
http://forums.sailboatowners.com/in...dc-electrical-foundation.181929/#post-1332240

The Short Version of the 1-2-B Switch Stuff: http://c34.org/bbs/index.php/topic,5977.msg38552.html#msg38552 This is a link to the Electrical Systems 101 Topic, reply #2

What are ACRs, Combiners & Echo Chargers? (by Maine Sail) [scroll to the top]
http://forums.catalina.sailboatowners.com/showthread.php?p=742417 and http://c34.org/bbs/index.php/topic,9404.msg70131.html#msg70131

They ALL come from this:

Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html
 
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Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
...The black box with fins looks like a diode based battery combiner or isolator. This allows the batteries to be connected for charging from a single source and blocks them from discharging into each other. They work, but have a significant limitation, in that there is a limitation on the charging voltage, it will top out at about 13.8 v. Not enough for bulk charging. ...
I believe that this is true only if you are using a charge source that is regulated at the source. If the voltage sense is at the battery the regulator will increase the output voltage by 0.6v at the regulator so that the battery gets the correct voltage. I have a combiner a smart regulator with sense on the house bank and have proper charging voltages at the battery. My charger is connected only to the house bank with no connection to the start battery so the combiner voltage drop does not affect it.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
so the combiner voltage drop
That's a new one on me. Combiners are simple relays, and unless the wiring is horribly undersized, or someone did it backwards by running the AO to the reserve bank and uses the combiner to recharge a depleted house bank, there should be no voltage drop. Or am I missing something? Wouldn't be the first time....:)
 
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NYSail

.
Jan 6, 2006
3,049
Beneteau 423 Mt. Sinai, NY
I’ll add my two cents....... those appear to be water drain / fill hoses wrapping around all those beautiful electrical devises. Water plus electric not a good combo and sure it may be fine for years but all it takes is one loose fitting or ruptures hose and you equipment is toast.

Greg
 
Jun 24, 2014
80
Westsail 28 72 Long Beach , California
Stu yes talking about the starting battery , that was my problem . House bank charging correctly , start batt. no charge . problem was 1-2- selector switch . Tighten the nut was the fix . But now I don't like that switch and it will be replaced .
Yes I know Maine Sail , I bought the charger from him . One of the reasons I bought from him was that I could talk to him , although he does have the best price on the charger . Maine also told me to ditch the Isolator , my electric guy told me to keep it .
Thanks for all the links I'll read them .

Hayden , thanks for the words . Question , why don't you have your charger hooked up to your starting batt. ? I have read your response a few times , obviously you know more about this stuff than I do .

All said and done guys for right now I'm up and running , next step change that selector switch .
Greg , you are so right . Actually what those are , they are bilge pump hoses .
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
Maine also told me to ditch the Isolator , my electric guy told me to keep it .
Your electric guy leaves a lot to be desired. That's why you are where you are now perhaps. It's good to see you're picking up on this stuff. None of us was born an electrician! Good luck.
 
Jan 11, 2014
11,324
Sabre 362 113 Fair Haven, NY
As far as cooked wires being left in place , come on give me a break well this the internet you don't know me .
Hey, the photo shows 2 blackish cables headed to the switch. Are they charred or just dirty? Can't tell from the photo, but they don't appear red at least on my computer screen. Lots of builders back in the day used welding cable instead of marine cable. The insulting jacket on welding cable is different than on marine cable and often gets really ugly and dirty. That could be the case on your boat, just can't tell from the photo.

I believe that this is true only if you are using a charge source that is regulated at the source. If the voltage sense is at the battery the regulator will increase the output voltage by 0.6v at the regulator so that the battery gets the correct voltage.
If the alternator is externally regulated and the sense wire is connected to the battery bank being charged, yes you are right. However, driving alternator voltages higher to compensate for the diode based combiner, increases the load on the alternator, increases the temperature of the alternator and if there is a temp sense on the alternator it will dial down the output voltage and you are back where you started with batteries being under charged.

In general I think electrical systems should be designed to be as efficient as possible. The diode based combiner is an unnecessary drain on the charging system.

As for solid wire and wire nuts honestly I have never had the covers off to check so I don't know I agree they all need to be R&R .
The problem with solid wire is the vibration on the boat causes the copper to work harden and then crack or break. That can lead to shorting, current loss, or corrosion in the wires.