Add a battery

[acudavid]

Hi Everyone! I am new to sailing. I started 10 months ago with a 50-year old Catalina 22, and three months ago, bought a 77 Lancer 30-2, which has a one cylinder Yanmar Diesel that runs well. I have two standard deep cycle batteries that get the job done. There is a charging system onboard that seems to work when the shore power is plugged in. They are wired through what I am calling a "battery bar". which has a place for (+) and (-) connections. I am guessing that they are wired in a series. (I crawled into my bilge to have a look but don't really know what I am looking at, access is very limited and I am considering installing a hatch behind the tiller for better access.) There appears to be available slots to connect two more batteries.

My question is this: It starts a little easier when it is cold and plugged into the shore power, than 3 hours later when I am returning to harbor. I use the heating switch for 10-15 seconds prior to starting, as I was instructed by the previous owner. Eventually, I will want to go on overnight trips and don't want to get stuck at anchor, trying to hand crank my diesel. When I start the motor in port--connected to the shore power, it generally fires right up. Three hours later, it makes a "wa wa wa" sound and then fires up. This is my first diesel. I don't know if this is normal or if I should add to the battery system, or possibly get a separate battery to start the diesel, and keep the other two for the boat?

Any help would be appreciated.
Thank you,
David

 

[Head Sail]

I would add a dedicated battery to start the engine. If the current setup is weak starting, your batteries could be tired or wiring is undersized or connections bad.

 

[rgranger]

I am guessing that they are wired in a series.

Probably in parallel. If your batteries are wired inseries then you would have 24V at the leads. Easy to find out. Just hook a volt meter to the leads at the terminal ends.

 

[Scott T-Bird]

Welcome to this forum! I think you have a lot to review regarding your electrical systems. I've found that learning about boat electrics is very satisfying and it should give you a great sense of security when you are confident about how everything is integrated and performs. Let's start with your batteries. Look for the tags on the batts that should tell you the age of the batts. I'd bet dollars to donuts that your batts are at least 5 years old and how do you even know that they "get the job done"? Without knowing anything about your batts, I would speculate that it might be a good idea to consider purchasing new ones. At least have them tested for capacity. They may be reaching the end of their service life.

So how are your batts wired to the switch? What is your switch? I'd guess it is the ubiquitous 1+2+B+Off switch. Your two batts may be wired in parallel (+ to + and - to -). That would be 2 batts combined to make 1 battery bank in 12 volts (I am assuming your batts are 12 volt). But if you do have Two 6-volt batts, they would need to be wired in series to make a 12 volt bank (+ to -). The other option is that you have 2 12 volt batts each wired to separate inputs on the switch. Our boats almost without exception run on 12 volt systems. Larger boats may have a 24 volt system, but you won't have that, I'm sure. You will need to define your system in greater detail by evaluating exactly to what the battery cables are attached,

As far as starting your boat with the shore power on ... I think that is not good. Are you saying that you are charging your battery while starting it? Don't you have an alternator? I don't think it is a good idea to start your engine while the charger is connected. If you have a functioning alternator, then you would be sending a charging current to the battery or batteries with 2 charging sources. I don't think that is kosher, but it may not be doing immediate harm. I ALWAYS disconnect shore power, or at least make sure the charger is off (open the charger switch on the panel) when I am starting the engine. Somebody may have better input about this.

On the subject of charging, you need to understand your charging systems and how charging is distributed if your batteries are actually separate banks. If you don't have a combiner or echo charger or smart charger or auto charging relay or some system of switch manipulation, you could be chronically undercharging one or both batteries. You need to describe what you have for anybody to be any help to you.

My personal preference for your boat would be to have 2 12v batts in parallel for a house bank and 1 12v batt start/auxiliary. I would do this with a DCP (Dual Circuit Plus) switch so that all I have to do is turn my switch on and both battery banks are in operation and separated between house loads and start loads. This requires 2 separate switches to provide isolation if that is ever necessary. This set-up does not necessarily have wide appeal, but it serves the purpose if done correctly. I will be modifying my new boat to eliminate the 1+2+B switch and replace it with DCP because I prefer separate house and start loads. The 1+2+B switch does not separate house and start loads. The loads are always combined with only the battery selection being altered by the switch position. It's a personal preference and you must make your own determination. Just know that there are alternative methods to serve our purposes.

There will be plenty of reading about it if you are interested. In any case, I believe your house loads will be best served with the capacity provided by 2 12v batts in parallel and your emergency needs (bank 2) can be adequately served by just one 12v battery.

You are going to get bombarded with reading sources ... just do it. Read everything and absorb as much as you can and ask questions. It will be fun! I promise!

 

[dlochner]

As far as starting your boat with the shore power on ... I think that is not good. Are you saying that you are charging your battery while starting it? Don't you have an alternator? I don't think it is a good idea to start your engine while the charger is connected. If you have a functioning alternator, then you would be sending a charging current to the battery or batteries with 2 charging sources. I don't think that is kosher, but it may not be doing immediate harm. I ALWAYS disconnect shore power, or at least make sure the charger is off (open the charger switch on the panel) when I am starting the engine. Somebody may have better input about this.

Multiple charging sources is not an issue if the charging sources are sort of smart and the voltages of the charging sources match the battery type. Second Star can have 3 sources operating at once (shore power, solar, and alternator) and frequently has 2. The regulating circuits on the charging source will determine which source is dominant and the battery's size and charge acceptance rate will limit how much of a charge the source is providing.

The only issue I have experienced when starting with shore power connected was blowing a fuse in the lead from the charger to the battery when the battery was weak. The surge from the starter quickly maxed out the charger and popped the fuse.

If the batteries are not able to start the motor or struggle after going for a sail, the batteries are toast. Time for new ones and probably a new charger. As batteries age their capacity declines. Volt meters can tell you how charged the battery is relative to its capacity, but they can't tell you the capacity. A battery that has a 100 amphour capacity when new, may only have 50 amphour capacity after a few years, although the voltages will look OK. Remember, 9 AAA batteries wired in series will give you 13.5 volts, but not enough power to start an motor.

If boat electrics are a mystery, start with learning the basics, Charlie Wing's Book (Amazon Link) is a classic and easily understood. It is an excellent starting point and worth every penny.

A second resource is Rod Collins's (aka Maine Sail) website (link below). Rod has done more help DIY boaters than almost anyone. His information is accurate and up to date. Take a look at the articles on batteries, there are many ranging from basic to more advanced. And be sure to read the message from Rod's brother on the home page. If the information is valuable, consider making a contribution. Much of what I know about boat electrical systems comes from listening to Rod.

Marine How To - DIY for Boaters - Marine How To

For DIY boaters in an attempt to try and keep the sport as affordable & safe as possible. How To articles for sailboats and powerboats.

www.MarineHowTo.com

 

[Richard19068]

The batteries are quite likely the problem but it could be possible that the wiring connections are coroded and limiting the voltage / amperage that is ending up at the starter and the extra voltage that is there when the battery is connected to the charger is helping to overcome the deficiency.

I would try cleaning the connections, particularly the battery negatives and engine ground, and see if that helps. Probably should be done anyway.

 

[twistedskipper]

I wouldn’t do anything until I’d confirmed the condition of the relevant wiring and the existing batteries. No point in reconfiguring or enhancing the system until you’ve done that.

 

[Ward H]

@dlochner pointed you to Maine Sail's website. which is excellent. Maine Sail is also a featured contributor to this website. The second thread here Musings With Maine Sail is a great discussion on the 1, 2, Both, Off switch.

I'm with @Scott T-Bird about using one battery bank for the house loads and one bank for dedicated starting.
Scott explains how to determine if you have two batteries in series or parallel.
While I also use the Dual Circuit Plus switch, you can also continue to use your 1, 2, both, off switch. Connect your "main" or "house" bank to one position on the switch. Then connect a "reserve" battery to the other position.
You can use your main/house bank for all purposes. House loads and starting your motor. If the main does not have enough juice to start your motor then switch to your reserve battery.

As the others said, check all your connections, check for markings indicating age of batteries and do some reading.

One other point, if your batteries are two 6 volt batteries wired in series, that may be good. There are several true deep cycle 6V batteries on the market. They can have a long service life. When it is time for new batteries, stick with flooded lead acid. Don't get caught up with the hype around AGMs or other specialized battery types. If someone suggest AGMs, there is a thread about them at the link I posted above.

 

[Scott T-Bird]

Look at the reading sources to understand what a wiring diagram looks like and then make a wiring diagram for your boat, including all electrical components, buss connections, wire gauges, fuse locations, fuse sizes, charging sources (alternator, shore charger, solar for example), system ground. The picture will start to become clear to you.

Really, you will find great satisfaction when you understand your boat electrics. It is a critical component of your boat and you will be happy to have confidence in your systems. I have a book called Sailboat Electrics Simplified by Don Casey that I started with.

 

[Justin_NSA]

Good advice here already. I might add, as a plan B carry a small jumpstart unit just in case.

 

[jssailem]

Hello @acudavid and Welcome to the SBO forum.
You have received a good intro into the skills here that can help you with your boat. @Scott T-Bird ’s, @Ward H and @dlochner

Have all given you good ideas to explore and implement.
All I might add is to start with a detailed inventory of what is on the boat. Batteries are not just batteries anymore (this is a boat not a car). They are a specific size and type. The details are important. Pictures help us help you as you learn the names and intricacies of your boat.

Congrats on your new bigger boat.
We are here to share our experiences both good and not so. No question is a bad one. All are good. Just keep us informed as to how it works out for you.

 

[Benny17441]

The boat's electrical system is 12V. You may have two 12V batteries connected in parallel or two 6V batteries connected in series. The trick to not getting stranded is, redundancy, to always have back up power . You can achieve redundancy with 1 pair of 12V batteries or 2 pairs of 6V batteries and a battery switch. A common battery switch has settings of Bat 1, Bat 2, Both, and Off. A properly wired switch will indicate by its setting from which battery or combination the power is being supplied. To achieve redundancy set the switch at Bat 1 or Bat 2 keeping the other one untouched and in reserve. Batteries have a finite number of charge/discharge cycles so in order to preserve the useful life of both batteries what it is regularly done is to alternate the use of Bat 1 and Bat2 at consecutive outings. In case of emergency the switch is temporarily set to Both to get the engine started and then returned to the Battery being used for that outing. When overnighting or weekending it might be a good idea to carry a fully charged automotive Battery Pack just in case your power usage would require to use both batteries.

 

[Richard19068]

In case of emergency the switch is temporarily set to Both to get the engine started and then returned to the Battery being used for that outing.

I think if the "emergency" is that the battery being used has gone bad you do not want to switch to both. This could cause the good battery to drain into the bad battery leaving you with two weak batteries. I think the proper thing to do would be to switch to the reserve battery to start the engine, wait for that battery to recharge and then maybe switch back to the bad battery to charge it. You want to make sure your switch will allow you to select different positions while the alternator is charging without disconnecting during the switch. I think most A B switches are okay with that these days. Ward H's link to Maine Sail's discussion of battery switches is a good one.

 

[DayDreamer41]

I am sure your head is spinning now, as you can see lots to learn about batteries and charging systems.
You mentioned that you were thinking of cutting an access hole in the cockpit, unless you can make this completely watertight (very difficult to achieve) I would not do it.

 

[acudavid]

Wow! I was not expecting so much helpful information. Thank you Head Sail, rgranger, Scott T-Bird, dlochner, Richard 19068, twistedskipper, jssailem , Benny 17441, Justin_NSA and DayDreamer41. I have some reading to do. For now, I've attached two pics of my batteries and hookup. I can't really see any identifying info on the types of batteries--24 dc or dcc or amp hours. They look like lead acid batteries. The one on the left has a sticker that reads: 8/19 and it looks fairly fresh. The battery on the right looks older and I can't find a date on it. All the connections and hardware look new to me. The previous owner spent a lot of money upgrading the electrical system. The receipts are cryptic, but I posted a third pic of the electrical panel with its battery switch and 12v and 120v meters.
The first pic shows the (-) connections on a bar of some sort, and the (+) connections go through what look like fuses (ANL 150 on the left and ANL 200 on the right)
The black plywood where the connections are mounted is actually the rear of the engine compartment. I can't readily see inside the compartment without removing the sides--which are inside the bilge. I am not as agile as I used to be so getting pics of the other side will be difficult. I am hoping that is not necessary.
There are two thinner cables that each contain a red and black wire mounted through the wood. The label on the cables reads "For Engine Battery Use This Bank Cable only" I am not sure what that means. My guess would be that one cable goes to the alternator and one goes to the onboard charger, but that's a guess.
Without any guidance, I would gamble and replace the older battery with a new 24dc Interstate from Costco (about $80) and see what happens.
I think I would rather separate the starting battery from house batteries. There is a place where I could mount a third battery right near the two batteries pictured. But I don't know if that is necessary. Right now, I only use the boat for 3-4 hour trips around the Santa Monica Bay. Eventually, I may want to take trips to Catalina or Channel Islands. I was thinking about what Justin suggested, and bringing a quick start just in case.
I have money for necessary repairs and I am not cheap. But my boat has zero navagational electronics, a compass that bounces so much I can't read it, a Windex that was stolen by a big bird, and as DayDreamer41 is concerned with water tightness of a hatch that I may install, there are already leaks all around my deck. I've spent days troubleshooting and repairing and now my starboard deck doesn't leak, but my port has 3 leaks--pretty sure I have to remove the toe rail to fix it, and there are two leaky upper hatches, one window, and two teak handrails that need to be sealed.
If I can get away cheap with the batteries, I can work on the other stuff on my list sooner. Thanks again for all of your help

 

[dlochner]

The batteries are indeed flooded lead acid batteries and are probably Group 24 batteries. Group 24, 27, and 31 batteries are all approximately the same height and width, they get longer as the number goes up and have more capacity. The Group 24 will have around 70 ah, the 27 around 90 ah, and the 31 around 100 ah. Measure the length of the battery and compare to the specs for a Group 24 battery. Most websites for battery manufacturers have the specs online.

Don't waste money buying a "marine starting battery" you will be better off with a "marine deep cycle battery." It will have a little more capacity and will easily start your motor. On the MarineHowTo.com website there is a good easy to understand article on "deep cycle" batteries.

The batteries look to be fused correctly, i.e., within 7 inches of the battery posts, however they should be covered to prevent accidental shorting, especially with the negative bus bar so close. It would be easy to have wrench slip and short the battery with a big spark, lots of noise and perhaps more serious consequences.

 

[Scott T-Bird]

That's a good start for making your wiring diagram ... As Dave says, the battery cables are fused at the battery and that's a factor of safety more than many boats have. It looks like you have just the one battery cable coming off each battery. There also seem to be some small wires connected to the positive posts with in-line fuses as well. It's not clear what those are for and you should trace them to where they go.

It appears to me that you have 2 independent batteries. They aren't in parallel and they obviously are not in series. It appears that the cables will go directly to the two source posts on your selector switch, which is the ubiquitous 1+2+B switch that most boats come with. We can see that you have the switch set to 1+2 (Both). That is not the recommended position unless you happen to be charging both your batteries. (It looks like you are with your AC shore charger on).

To understand what is going on, you have to understand your switch. This switch has 3 posts. There are 2 source posts and 1 load post. Your battery cables look to be attached to Post 1 and Post 2 source posts (the batteries are the source of your power). Your engine starter and your house panel are connected to the C post. The C post is a common load post. When you put the switch in the 1+2 position, you are essentially operating your 2 batteries in parallel (even though they aren't wired in parallel). There is a reason for doing this. In the absence of having a charging relay or an echo charger, sailors use the selector switch to manage the charging regimen. In order for the alternator or a shore power charger to charge the desired battery, if they are wired through the switch, then the battery that is intended to receive the charge has to be selected with the switch.

Find out how your charging sources are wired. Your alternator may be wired to your starter, which back-feeds the charge to the selector switch through the starter cable. This is a very common set-up as provided by the boat builder, unless the previous owner changed it, which he might have. Find out where the shore power leads are connected for sure.

 

[Scott T-Bird]

There are two thinner cables that each contain a red and black wire mounted through the wood. The label on the cables reads "For Engine Battery Use This Bank Cable only" I am not sure what that means. My guess would be that one cable goes to the alternator and one goes to the onboard charger, but that's a guess.
Without any guidance, I would gamble and replace the older battery with a new 24dc Interstate from Costco (about $80) and see what happens.
I think I would rather separate the starting battery from house batteries. There is a place where I could mount a third battery right near the two batteries pictured. But I don't know if that is necessary.

I don't really know what that label means, either. The best way to find out is to trace the wires and find out what equipment they are linked to. It could be that the previous owner linked the alternator cable to just one battery. Keep in mind that if you really want to isolate a start battery from a house battery, they won't be isolated with that selector switch. The load post is common to both loads if you have just the single selector switch. I think it is worthwhile, if you are going to do moderate cruising, to have a pair of batteries for house loads and a single auxiliary battery for emergency. I would remove the oldest battery and get an identical pair of new batteries and wire them in parallel for the house bank. Your newer battery is 2019 and is probably just fine for the auxiliary battery. It appears that the previous owner knew how to care for the electrical system, so I doubt he mismanaged the batteries. If both existing batteries are functioning well, I would probably leave well enough alone for a year or so and see how your electrical needs develop for a while. Only replace the older battery after you determine your desires and it becomes necessary to change the older battery out.

 

[sesmith]

Ditto, what everyone else has said especially learning more about how the boat is wired.

There is the question of whether the batteries are weak or there's some issue with restarting the engine hot, though. I also suspect the former, but a quick test is to charge the batteries, then leave the shore power disconnected over night. If it fails to start in the morning, or starts slow, you know there is no hot start restart issue with the motor. One possibility eliminated. You then can work on determining whether the batteries are weak, there's some unknown draw on the battery, or a problem with wiring to the starter or start solenoid switch. FWIW, you should only need to glow it first thing in the am. Diesel's stay warm for quite a while.

 

[Richard19068]

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?

I would try sesmith's suggestion of seeing how the engine starts after a night without the charger on.

What voltage do the batteries show when you first get to the boat with the charger on?
What voltage shows before starting the engine after sailing for the day (or after a night without the charger)?
If you have someone sailing with you have them observe the volt meter to see how far it drops when you try to start the engine after
sailing for the day or after a night without the charger and see if there is a large voltage drop.

Have you checked the water in both batteries?