The Great Battery Dilemma

[Eric Gordon]

I am, at heart a very simple man.

When I first purchased Sea Star in 2016, I knew absolutely nothing about owning and operating a sailboat of any kind. It can still be said that little has changed. Sure, I can blame about two-years of inactivity on Covid, but, the rest of it is on me.

So over the past 60-days as I have dived back into boat projects, one of the things that I needed to address was power on Sea Star.

The PO, had three batteries, which powered the engine and a wide assortment of sailing accouterment, including RADAR, a half-functioning, button operated airhorn, a stereo system with speakers, a refrigeration system, lights (interior and running), a Lofrans Project 1000 windlass, a macerator, depth sounder, compass light, speed instrument, VHF, and a whole bunch of other little things.

Fast forward to today and I have eliminated almost all of the things I dont want on the boat, either because I simply want things simple, or, as in the case of the refrigerator/cooler system, the thing was all rusty and disgusting.

So a few weeks ago, I began to realize that SOME of the tasks on Sea Star could be accomplished by me, albeit, they would simply take more time. And time, (your favorite non-denominational or exalted being willing), is something I have plenty of.

So I bought a couple of new West marine batteries, and a NOCO charger and installed them. That alone was a harrowing experience, because I have little confidence in swimming about in the mass of cables left by all of those things which needed to be removed, but I got through it and things are working.

So, long story short, I have two West Marine AGM Class 100 Batteries powering the following;
- VHF
- Interior lights (a total of about 4)
- Running lights
- Engine Starter
- Depth Sounder (currently on the fritz)
- Knot Speed Indicator (currently on the fritz)

I want to add the Windlass to the House battery and I wonder: given there is no longer Radar or a macerator or any of the other stuff sucking up power, do you think I will be OK if I have the windlass hooked up to the existing system or would I be better off with a third battery?

And, I would like to run an inverter on the house battery so when I sail down to Oceanside or San Diego, I can run a CPAP or boil some water (no gas stove on board).

Am I talking myself into a third battery?

As always, your thoughts and advice are a welcome learning experience.

You would have thought that, at 70, I would already know some of this %#^@.

 

[peaman]

You might want to consider installing a battery monitor, like one offered by Victron. Soon after I bought my boat, and unfamiliar with electrical capacity and loads, I installed one and it is a constant source of comfort. I can quickly see the voltage of each bank, and the percent of capacity remaining on my house bank. I can also see current draw at any time, a capability which I used to document the load imposed by each device and system in my boat. Installation and setup were both straightforward.

 

[Eric Gordon]

I actually do have an older one installed that came with the boat. It is a Blue Sea Systems, 3 bank (switchable).

I do notice that after I installed the new batteries no matter what position the Blue Sea switch is in, it shows essentially the same voltage.

 

[Loren Beach]

It seems basic, to me anyway, to have only two battery "banks" on a smaller boat. Smaller, like an E- 27 or my 34. That's an opinion, and no way an expert one.
One larger (higher amp hour) bank for everything including engine starting and all other loads.
The second being an emergency bank if the first bank fails. 99% of the time it lives a hermit's life, awaiting a call to action...

I do have a monitor (*) and it pleases me to instantly check the % of charge of the house bank, and to read the voltage or ether bank.
I still have the factory master switch, a "one two, all" rotary switch.
Have you a sketch of the present system to share with us?

* https://balmar.net/wp-content/uploads/2018/05/PDS-44-SG-1224.pdf

Regards,
Loren

 

[Eric Gordon]

How embarrassing. When I replaced the batteries a couple weeks ago, I did the best I could to put cables where they had been before the battery failure. In any case there is a LOT that I do not know. So I quickly sketched what I do know, and I realize I need to get smart about this.

Everything seems to be working…but if I had to troubleshoot anything, it would take me a while because of my lack of knowledge about where everything is going.

So this sketch is incomplete to say the least.

 

[Eric Gordon]

How embarrassing. When I replaced the batteries a couple weeks ago, I did the best I could to put cables where they had been before the battery failure. In any case there is a LOT that I do not know. So I quickly sketched what I do know, and I realize I need to get smart about this.

Everything seems to be working…but if I had to troubleshoot anything, it would take me a while because of my lack of knowledge about where everything is going.

So this sketch is incomplete to say the least.

Also, I’m unsure about the distrubution bar near the engine, other than the fact that I assume it has something to do with the engine charging the batteries while its running. Mine looks verrry old….so maybe replacing that will help me understand a little more about where everything is.

 

[KS Dave]

I would also add that pictures of things you have questions about are very valuable in helping you discover what they are.

Regarding your path of learning, here are a few resources I can heartily recommend:

1) MarineHowTo - Rod has a lot of great articles on marine electrical (and other great topics).
2) Nigel Calder - he has a YouTube Channel with lots of great content. Also, his books are a gold-standard resource.
3) Jeff Cote from Pacific Yacht Systems has an excellent Marine Electrical Seminar series on YouTube that will run you through the basics.
4) I'm not a huge Facebook guy, but Rod moderates a group (that a lot of industry professionals also participate in): Boat Electrical Systems.

 

[Loren Beach]

E32-3 - Part 1--A Novice's Guide to Panel Reorganization

A yacht distribution panel that is a bad hair day from the 1980s is easy to ignore if the boat electronics sort of work. When I changed stereos last year I just crimped and crammed the new wires in. Then a few months later came a new GPS. Soon I...

ericsonyachts.org

Different Ericson model, but the concept seems valid. First, expand on your drawing with labels on what you are starting with.
Hopefully, some other owners of same vintage boats can chime in with more information also.

I had to draw up a diagram of all of my boat's higher-amperage wiring commenting my batteries, engine, and the feed to the DC distribution panel. It was... satisfying... after it was done.

 

[peaman]

So this sketch is incomplete to say the least.

If it is like mine was originally, you will have a cable from the battery switch to the engine starter motor, another from the starter to the alternator, and another from the battery switch to the "house distribution". I'm not sure what your "distribution (near engine)" is. As I recall, my engine circuit gets power from the starter motor lug where the alternator and battery switch are connected.

With that arrangement, you don't really have a "start bank" and a "house bank", because both banks are identical in that when the battery switch is switched to one bank, all house loads, engine loads, and start load come from that bank and the alternator charges that bank only. And that's all fine as long as you keep in mind what position the battery switch is in. When the engine is running, you might want to have the battery switch to the "both" position so that both banks get charge, but when you shut the engine off, you will want to select one bank or the other so that one battery is reserved for starting the engine later. The windlass is kind of special, since it is typically a substantial load. On bigger systems, the windlass is sometimes powered with a dedicated battery, but in your case, you probably will just want to run the engine when using the windlass. Or at least make sure that when using the windlass, the battery switch is at 1 or 2 while reserving the other battery for starting the engine later.

Before changing any cables or wiring, you will want to consider the correct wire size.

Edit to add: Assuming you have a built-in battery charger running from shore power, that will typically have a cable to each battery positive and each battery negative terminal.

 

[Eric Gordon]

E32-3 - Part 1--A Novice's Guide to Panel Reorganization

A yacht distribution panel that is a bad hair day from the 1980s is easy to ignore if the boat electronics sort of work. When I changed stereos last year I just crimped and crammed the new wires in. Then a few months later came a new GPS. Soon I...

ericsonyachts.org

Different Ericson model, but the concept seems valid. First, expand on your drawing with labels on what you are starting with.
Hopefully, some other owners of same vintage boats can chime in with more information also.

I had to draw up a diagram of all of my boat's higher-amperage wiring commenting my batteries, engine, and the feed to the DC distribution panel. It was... satisfying... after it was done.

If it is like mine was originally, you will have a cable from the battery switch to the engine starter motor, another from the starter to the alternator, and another from the battery switch to the "house distribution". I'm not sure what your "distribution (near engine)" is. As I recall, my engine circuit gets power from the starter motor lug where the alternator and battery switch are connected.

With that arrangement, you don't really have a "start bank" and a "house bank", because both banks are identical in that when the battery switch is switched to one bank, all house loads, engine loads, and start load come from that bank and the alternator charges that bank only. And that's all fine as long as you keep in mind what position the battery switch is in. When the engine is running, you might want to have the battery switch to the "both" position so that both banks get charge, but when you shut the engine off, you will want to select one bank or the other so that one battery is reserved for starting the engine later. The windlass is kind of special, since it is typically a substantial load. On bigger systems, the windlass is sometimes powered with a dedicated battery, but in your case, you probably will just want to run the engine when using the windlass. Or at least make sure that when using the windlass, the battery switch is at 1 or 2 while reserving the other battery for starting the engine later.

Before changing any cables or wiring, you will want to consider the correct wire size.

Edit to add: Assuming you have a built-in battery charger running from shore power, that will typically have a cable to each battery positive and each battery negative terminal.

I am going to have to recheck this, but I believe you’re correct, in that my batteries are configured in the way you mention, which may be the reason my battery monitor shows the same voltage no matter what position I put it in.

Also, I’ve always heard/read that I shouldn’t change the switch during motor operation. That said, I suppose I could start the engine with the switch to “ALL."

I do have the NOCO charger hooked to each battery separately.

 

[Eric Gordon]

E32-3 - Part 1--A Novice's Guide to Panel Reorganization

A yacht distribution panel that is a bad hair day from the 1980s is easy to ignore if the boat electronics sort of work. When I changed stereos last year I just crimped and crammed the new wires in. Then a few months later came a new GPS. Soon I...

ericsonyachts.org

Different Ericson model, but the concept seems valid. First, expand on your drawing with labels on what you are starting with.
Hopefully, some other owners of same vintage boats can chime in with more information also.

I had to draw up a diagram of all of my boat's higher-amperage wiring commenting my batteries, engine, and the feed to the DC distribution panel. It was... satisfying... after it was done.

I think Christian’s experience is in my near future.

I’ll try and send pix of the maddness when I get back to the boat tomorrow or Friday, because I have a number of questions, But for now, I wonder what your thoughts are of initially just changing all of the old crusty hardware in the system, because the wiring looks fairly new. When I purchased Sea Star in 2016, the PO told me that the person he purchased it from had put new engine and wiring in as recent as the early 2000’s. I’m talking about replacing any of the hardware like positive/negative busbars, the battery isolator, old toggle switches, etc….

 

[Prairie Schooner]

One thing you could check is whether the existing wire is tinned. That would give you some idea of its vintage. The original wire on our boat is not. I'm not sure when that ABYC standard was instituted.

 

[Eric Gordon]

One thing you could check is whether the existing wire is tinned. That would give you some idea of its vintage. The original wire on our boat is not. I'm not sure when that ABYC standard was instituted.

Ok, will do. The attached photo is from a website, but much of the triplex cable in the boat looks exactly like this. I’ll check when I get to the boat.

 

[Kenneth K]

Also, I’m unsure about the distrubution bar near the engine, other than the fact that I assume it has something to do with the engine charging the batteries while its running. Mine looks verrry old….so maybe replacing that will help me understand a little more about where everything is.

A "distribution" bar located near the engine is likely one of two things; you'll have to figure out which.

First, a ground bus bar is often placed near the engine to "collect" all the grounds from various sources (batteries/banks, the DC panel, the engine panel, battery monitors, etc). It collects all the grounds and then connects them to the engine with a single, high-amperage cable (usually a battery cable). Note that devices that are already attached to the engine block (the alternator, glow plugs, temp/pressure senders) don't need ground wires because they are already grounded to the engine. Here is a typical ground bus bar installation:


Second, a terminal bar is usually located somewhere near the engine. The collection of wires that stay attached to the engine is know as the "engine harness." It typically contains wires for the engine panel, engine instruments, the starter switch, glow plugs, etc. Since these wires stay attached to the engine (even when the engine is removed), there needs to be a way to connect these circuits to the boat's electrical system. From the factory, Ericson did this with "trailer plugs," which are know to cause problems over the long term. A much better way to make these individual connections is with a terminal bar:
Terminal Bar: VS: the old trailer plug:



So, Note the difference between the two types of connectors: A Bus Bar is a collection of POS or NEG circuits brought together as a single, common circuit. A Terminal Bar contains many individual circuits that are not connected in common (and, may contain both positive and negative circuits).

For more info on the engine wiring harness and the engine panel itself, here's a post of my engine panel re-wiring: https://ericsonyachts.org/ie/ubs/another-engine-panel-upgrade-pt-1.701/

 

[Christian Williams]

A small inverter easily powers a laptop. But when I looked into an inverter just to power a small coffee maker, I backed off. An inverter to boil cooking water was a bridge too far. Even a hair dryer.

The forum could use a knowledgeable discussion of sailboat inverters, sizes, and utility vs. a genset.

My sense of electric windlass load is that operating duration is short, so massive battery bank not required. But wire runs are expensive.

Calculation can give confidence in custom installations, if you happen to have confidence in your ability to calculate. I don't, so I hire an electrician for AC or anything beyond simple 12v installations.

 

[bsangs]

Calculation can give confidence in custom installations, if you happen to have confidence in your ability to calculate. I don't, so I hire an electrician for AC or anything beyond simple 12v installations.

I'm with you, Christian. Have become pretty comfortable fooling around with my 12v wiring, but once the AC current is involved, I'm on the horn with my electrician. Learned my lesson after frying myself a few times over the years trying to Tim Taylor some AC things in my 1927 home.

 

[Prairie Schooner]

Ok, will do. The attached photo is from a website, but much of the triplex cable in the boat looks exactly like this. I’ll check when I get to the boat.

Btw, I'm not suggesting you replace all the old stuff. That's a major undertaking. But that bit of evidence might help you do forensics on what's been done.

 

[Eric Gordon]

I actually do have an older one installed that came with the boat. It is a Blue Sea Systems, 3 bank (switchable).

I do notice that after I installed the new batteries no matter what position the Blue Sea switch is in, it shows essentially the same voltage.

This is the one I have on my boat.

 

[Vtonian]

Timely discussion. I'm literally neck deep in this stuff now, having made dozens of trips into the bowels of the lazarette and stuffed my head into tiny places where no head should be. Yoga is not my thing and sometimes, when I feel myself cramping up in a particular contortion, I wonder if anyone has ever been found dead from starvation, with their wadded up body lodged in some sailboat cubby hole with a dislocated shoulder and a belt loop snagged on a hose clamp. I also figured out why sailors wear knit hats all the time: a helmet is too big but padding is essential.
That said, knowing where you are is the best place to start and there's no crying in sailing, so back I go...