Add a battery

Oct 26, 2008
6,045
Catalina 320 Barnegat, NJ
Does anyone think it odd that the battery charger appears to be on (indicator is glowing) but the battery voltage meter is only reading about 12.5 volts?
Yes, it does seem odd. I wonder if there is explanation ....
it wouldn't hurt for @acudavid to install a battery monitor. A Balmar SG200 is useful and a very simple installation!
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
I agree with @Scott T-Bird the Balmar SG200 is a great monitor. They are a bit expensive, but a good tool on board if you are going to be cruising and anchoring away from the marina and need to rely on your batteries for multiple days.

If you are a day sailor or local racer, I believe with limited resources, funds are best put into sails and sail management hardware. You can rely on a decent battery charger to keep the batteries charged. The typical 12 volt battery at $150 or less will last in these conditions for several years (like your car battery). Then you exchange it out and replace. In which case a more modest costing "battery charge indicator" makes some sense.

On the other hand if you plan to coastal cruise and anchor out away from shore power for multiple days, the cost of the more powerful Balmar or Victron units gives you a much better understanding of the batteries status, you rely upon for night lights...

There is no one size fits all on a sail boat. If you got the cash then why not spend it on your boat. The real joy I find is that it is Your Boat and no one can tell you what you must have.. Save the Coast Guard and their safety regs.
 
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Nov 11, 2021
38
Lancer 30-2 Marina Del Rey
Richard19068 said:


Does anyone think it odd that the battery charger appears to be on (indicator is glowing) but the battery voltage meter is only reading about 12.5 volts?

Thanks Richard19068 and Scott T-Bird. The meter on the top left is for the 12 volt system. There is a meter on the right for the 120. jssailem has my pattern down--day sailing for at most 4 to 5 hours in the Winter months, two or three days a week if I can. An expensive electrical monitor is probably overkill for my current needs. If I have any issues, I will add a starting battery before I go on any overnight voyages. I decided to start by replacing only the older of the two batteries. The one dated 8/19 seems to be ok. It works (short term) fine when I select only it from my battery switch. So I replaced the old looking battery with no date with an Interstate dc 27 that I got from Costco for $99.65 with core after tax. I don't think it was much of a gamble, mostly my time--and I got to practice my "boat yoga" for about 20 minutes. The Costco batteries are not fully charged. I replaced the battery just before nightfall. It has been charging overnight and I plan to go sailing today. I will let you all know.

dlochner, you were right about shorting! I am not sure what my wrench hit when it slipped, but there were sparks! Glad my fuel tank is diesel. I will figure out how to cover my posts.

When I update on, hopefully a successful battery replacement, I will post pics of my bilge and where the batteries reside. I am thinking about trying to raise them in case I ever take on water. Being a newbie to sailing, I try to watch youtube-type videos of both how to sail and what to be aware of. I saw a video where a thru-hull failed and the batteries quickly were under water, which resulted in no electric bilge pump. I will keep the forum posted.

Thanks everyone!
 
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Ward H

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Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Thanks Richard19068 and Scott T-Bird. The meter on the top left is for the 12 volt system.
What Richard19608 noticed is your 12 volt meter is showing 12.7 volts while your charger is turned on. Battery chargers charge at a higher voltage, usually around 13.6 volts. A fully charged battery, when sitting at rest for a few hours after being charged will show 12.7 volts.

The voltmeter may be indicating that the charger is not working, something for you to check. It may also be due to voltage drop due to a poor connection.

Try turning off the battery charger and note the volt reading. Then again with the charger on and once again with the charger off and motor running. You should see an increase in voltage with either charging source on. If not, the charging voltage is not reaching the batteries or they have failed.
 
Jun 11, 2004
1,621
Oday 31 Redondo Beach
What Richard19608 noticed is your 12 volt meter is showing 12.7 volts while your charger is turned on. Battery chargers charge at a higher voltage, usually around 13.6 volts. A fully charged battery, when sitting at rest for a few hours after being charged will show 12.7 volts.

The voltmeter may be indicating that the charger is not working, something for you to check. It may also be due to voltage drop due to a poor connection.

Try turning off the battery charger and note the volt reading. Then again with the charger on and once again with the charger off and motor running. You should see an increase in voltage with either charging source on. If not, the charging voltage is not reaching the batteries or they have failed.
Thanks Ward. I should have been more specific.
 
Oct 26, 2008
6,045
Catalina 320 Barnegat, NJ
@acudavid , if you have a multimeter, put it on the battery posts while it is charging (and resting). Perhaps your meter is off. @Ward H is right about the voltage in float mode at 13.6 (which is what we would assume at this stage). In bulk charging mode (when your battery is drained and you just start charging) you should probably see about 14.3 volts. What Richard's keen eyes were picking up is that your battery voltage seems too low for a charging battery. If you don't have a multimeter, it would be handy to get one.
 
Nov 11, 2021
38
Lancer 30-2 Marina Del Rey
@Ward H @ Richard19068 and @ Scott T-Bird I had already left for my boat before these posts came in, and as a rookie, I honestly didn't look closely at the 12 volt meter to see if it read above 13, I thought anything above 12 was fine. I will be back at the marina on Sunday and will look then. In the meantime, the new Interstate dc 27 is in place. The diesel fired right up, I sailed for 3 hours, and then as I approached the harbor, the diesel fired right up with no hesitation. No "wawawa" during the restart. Of course, one ride does not make for a reliable test, but I will advise the forum.
Right now my switch is set to 1 + 2, The new battery is on 2. I will try the "2" and "1" positions singly to see if the old battery seems weak. I know the prudent thing is to remove the old battery and have it checked, but I'm not sure I am ready for the bilge. I am 63 and my body is starting to remind me of that old Bob Villa show "This Old House". When the soreness subsides, I will be ready for round 2. I am thinking that replacing the two year old battery with another new Interstate dc27 may be a good use of $100. Right now, and it may be soon to tell as this is not a measure, but my house lights are brighter with the switch set to "2" and the new battery, then when set to "1" with the old. That leads me to suspect the old battery is weak.

About the 12 volt meter reading 12.7, the existing stereo was playing when I took the photo of my electrical panel. It is an old car stereo that is wired to the 12 volt system. I don't know if this would cause the reading to be low.

Thanks to everybody for the assistance!
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
@Ward H @ Richard19068 and @ Scott T-Bird I had already left for my boat before these posts came in, and as a rookie, I honestly didn't look closely at the 12 volt meter to see if it read above 13, I thought anything above 12 was fine. I will be back at the marina on Sunday and will look then. In the meantime, the new Interstate dc 27 is in place. The diesel fired right up, I sailed for 3 hours, and then as I approached the harbor, the diesel fired right up with no hesitation. No "wawawa" during the restart. Of course, one ride does not make for a reliable test, but I will advise the forum.
Right now my switch is set to 1 + 2, The new battery is on 2. I will try the "2" and "1" positions singly to see if the old battery seems weak. I know the prudent thing is to remove the old battery and have it checked, but I'm not sure I am ready for the bilge. I am 63 and my body is starting to remind me of that old Bob Villa show "This Old House". When the soreness subsides, I will be ready for round 2. I am thinking that replacing the two year old battery with another new Interstate dc27 may be a good use of $100. Right now, and it may be soon to tell as this is not a measure, but my house lights are brighter with the switch set to "2" and the new battery, then when set to "1" with the old. That leads me to suspect the old battery is weak.

About the 12 volt meter reading 12.7, the existing stereo was playing when I took the photo of my electrical panel. It is an old car stereo that is wired to the 12 volt system. I don't know if this would cause the reading to be low.

Thanks to everybody for the assistance!
If the charger is on it should be able to keep up with a load like a stereo and stay around 13.3 volts. Some chargers have a California compliance mode where they basically stop charging shortly after the battery is full. That’s not necessarily the most battery friendly but it could explain the voltage reading.

Now that you have two dissimilar batteries I’d recommend only having the 1-2-B switch on both when you’re actively charging. Discharging while on both is not ideal. Of course that leaves you in a position of choosing to sail while using the old weak battery and saving the good one to start the engine, or sailing with the strong battery and risking draining it too far and needing to try to start with the weak battery. Neither case is really great, so if it were me I’d probably replace the other old battery and keep an emergency jump pack just in case.
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Good for you to get out and on the boat.

With one battery you know the status and one that is unknown, it is best to keep them separate. The weak battery will drain the good battery. The good battery will sacrifice itself to try and balance out the two batteries. You end up with 2 weak batteries.

My motto on a mature boat. If it works then leave it be. If it is weak and of unknown age/history - replace it if it is important to boat operations/safety!

Keep sailing. Soon it will be like riding a bike.
You’ll think less and enjoy more.
 
Oct 26, 2008
6,045
Catalina 320 Barnegat, NJ
@acudavid , you keep reading our posts and this forum and we'll have you looking at all kinds of things you never thought to look at! :biggrin: I don't blame you for not paying much heed to a meter that reads over 12 v. I'd not be surprised if what David said above could be the case. Identify the charger next time you are looking. Also, when you put the selector switch on B (or 1+2) you are essentially combining your batteries, which is not recommended, except when charging. Think of the old battery essentially pulling the new battery down to its level of health. It can be harmful to the new battery, but it isn't necessarily the end of the world for it, either. Just keep it in mind. The 1+2 position is primarily used to charge batteries simultaneously, but it's not recommended for discharging the batteries simultaneously.
 
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Nov 11, 2021
38
Lancer 30-2 Marina Del Rey
Hi Everyone!
I decided to take the good advice of Davidsailor26 and others, and do the smart thing and replace both batteries. I now have two Interstate 27dc batteries. Before I made the decision, I disconnected the shore power, put the switch to "2" which is the new battery, and it read 13 volts. Then switched to "1'" the old battery, and it read 11.8 That made my decision. Now the boat starts right up.

I am wondering about the charging. The 12 volt meter reads 13.5 in the am after being plugged into the shore power all night. Then when I disconnect, start the motor, it goes down to 12.8. This is for the "1+2", the "1", and the "2" reading. After about about 5 minutes, it still reads 12.8. I don't know if this is normal.
It is difficult to see the charger. I will have to take the internal port cover off to get a chance to read it. If I need to, I will get the model number.

If the readings sliding down to 12.8 are not normal, than I will take pics of the charger. As of now, the motor fires up much better than before.

I did take some good pics of my bilge and would like advice if I should try to raise my batteries. I am guessing this should be a second post? Please let me know.
Thanks to all!
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
What you are describing is pretty normal. The 13.5 voltage is the float voltage. It is a low current stage that just keeps the batteries topped off and compensates for the battery's self-discharge rate and any small loads.

12.8 v is a pretty typical voltage for a new battery that is fully charged after a few hours off of the battery charger. When a charger is disconnected, the battery voltage will remain high (~13+v) for up to 24 hours, before settling down to its normal voltage level.

When you get a chance take a photo of the charger. It is probably one you will want to replace. Modern chargers are kinder to the battery which encourages longer battery life.
 
Nov 11, 2021
38
Lancer 30-2 Marina Del Rey
@dlochner
I was able to take some pics. The charger looks newish. It is a ProMariner ProSport12, which seems to be the 3rd generation. The 4th generation--called ProSportHD12-- is widely available, and Amazon still has one vendor selling the ProSport12. I can't see any identifying numbers on the front and it is mounted securly. I don't know if the brand is good, but it seems to be working.
The prior owner spent nearly a thousand dollars updating the electrical system onboard. The electrical panel that has the meters was replaced. The receipt is cryptic to read, and there are no line items, but I would not be surprised if the charger is about 2 years old. Please let me know any thoughts or advice.
My next project is checking thru-hulls. I have 3 aft and 2 foreward, and the bottom needs paint. When I get complete pics I will post. Is "ask All Sailors" the best place to post? Thanks
 

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