Battery Systems

[Hydrospud]

Can anyone recommend some references to understand boat battery systems in general. We have a 2003 Mainship 400 and would like to run the generator less, be sure we have enough power to start the main engine, and manage our batteries for maximum battery life.
Thanks

 

[ranger58sb]

One ref might be Nigel Caulder's "Boatowners Mechanical and Electrical Manual.

And then there are boatloads of threads here about batteries and electrical systems... although they tend to be either problem specific of all over the map.

Say some more about what you're trying to solve. What batteries do you have now? What are you trying to run longer without generator?

Some of the easiest solutions are simply to add more battery capacity... assuming real estate availability. Several ways to do this...

-Chris

 

[DavidM]

Most boats straight from the factory have two batteries or battery systems. One is connected to the 1 terminal of the 1,2,all,off switch and the other is connected to the 2 terminal. You select which one(s) you want to use with the switch. Often they are the same size and type- so-called dual-purpose batteries.

The first thing I would do if you have two dual purpose batteries is to select one as your house bank and add another. This will double the time at anchor. Even better is to replace the battery with two golf cart batteries wired in series. That will more than double the time at anchor.

After that this list is almost endless. Here are some suggestions in order of importance:

1. Install a shunt based battery monitor on the house bank.

2. Install an ACR or combiner to automatically charge both banks

3, Install a solar system to keep the batteries charged while at anchor.

Etc.

David

 

[Scottwb96]

Need A LOT more info about your current setup... But Nigel's books are a good start.

 

[wkearney99]

"generator less" depends entirely on what it is you're expected to have powered and operating without it.

You're also at the mercy of understanding not only what was installed by the factory, but what might also have been done in the intervening years between that time and your current ownership.

It's best done, step by step, circuit by circuit, to map out what's connected to where. This is time consuming and can get pretty darned expensive if you're paying someone else to do it.

Two big things that consume wattage are AC and refrigeration. Followed closely by navigation displays. Sunlight readable displays can pull some serious wattage.

So once you know what you've got onboard, and how it's *presently* connected/powered then you can start making an electrical budget to determine how to get to "run the generator less".

 

[Slowmo]

You can add more battery to increase time without running the generator but you have to consider how you charge the batteries. Larger batteries=more charge requirement. Large alternators and good regulators (e.g. Balmar) help if you run a lot. Solar is quite popular especially with sailboats to avoid running the generator. We have lots of battery, I find the generator or shore power charges them much faster than the engine because the inverter can put out 150A.

 

[wkearney99]

...I find the generator or shore power charges them much faster than the engine because the inverter can put out 150A.

And you can put a larger alternator on the engine but understand that will add load to the engine. TANSTAAFL applies.

 

[Bacchus]

Peter
Welcome to the world of Mainship and TF.
If yours is like many / most MS I have become familiar with it likely has a pair of 8Ds for combination start & house and a 3rd 8D for thruster (if applicable). In addition MS used diode isolators which are not the best approach with other more modern options available.
Above is how mine was set up and I never liked the combination house / start arrangement. My website - projects section has a write up re charging mods I made to the charging system. Since then I have moved the eng start to my thruster bank and added a Balmar monitoring system. I now have a pure house bank of 2 8D AGMs and my start / thruster 8D AGM. Gen batty is completely separate and charged by the Gen. On advice from another TFer when I did my mods I replaced my Gen on/off Sw with a 1-2-all-off sw (same footprint & bolt holes and added a jumper to my house bank that allows starting / boost via the house and connection of the alt & shore charger for the house topping off the gen batty. My 8Ds are a legacy of what was there and before I started making mods. When they go my plan is to replace each w/ a pair of GP31 AGMs but that is another whole story.

I agree the Nigel Calder book is a great start as are the many threads here on TF.
The issue you will have is there are several acceptable / good ways to skin this cat and you will find folks with their preferences and prejudices.
More info on what you have, how the systems are configured currently and what your objectives are will prompt more specific recommendations. Then the challenging part - which of many approaches to choose??

If you are not familiar with Steve Cyr's Stella Blue website it is a wealth of info on Mainships and his (previous) 2003 400 in particular Stella Blue Home
Happy to answer questions about what I did and why but realize it may / may not be the best to satisfy your wants, needs and preferences.

 

[Flatswing]

Here’s what helped me gain useful knowledge and make informed decisions about my battery systems & changes. I started pretty much from where you appear to be:
1) Read Nigel Calder
2) Crawl around your boat and make a diagram of how everything is connected - 12V then 125/250V
3) Repeat Step 1
4) Don’t hesitate to reach out to experts such as Jim Healey if you are stuck.
5) Decide upon & implement changes best for YOUR usage

 

[Derek]

Great responses. Previous boat was a MS 400 and wish I had asked the same question before putting in the inverter. Have a MS 430 aft cabin now and it is set up exactly as described by others from the factory. The company working with me on inverters suggested we keep the existing batteries as is and put (6) golf cart batteries under the bed and dedicate them to the inverter. However another person suggested just expanding the existing design but take out the legacy 8D’s and put (4) 4D AGM’s in place acting as a pooled start/house bank like it is now. Still undecided.

 

[HeadedToTexas]

I replaced my Gen on/off Sw with a 1-2-all-off sw

Good stuff, Don. Why did you go with the 1-2-Both-Off switch instead of Auto Charge Relays? After reading up on the ACR, my plan is to replace the 1-2-B-O switch with a pair of ACRs to better take care of what keeps me up some nights. What am I missing?

 

[Bacchus]

Vince
I did opt for a Sterling relay for alt charging of the (then) start/house and thruster banks (I've since moved start to thruster bank). I provide more info in the Bacchus website article and did consider a couple different relay mfg. I was concerned that if I operated thrusters when batty banks were connected I could get a hi A "back flow " from house bank to thruster bank... could the relay handle it or burn out? Sterling (and CMS said it was a perfect application and no problem)
I didn't feel another ACR was a high enough need / priority when the Sw provided the back up gen start capability.
While the gen alt provides the charging for gen to be independant combining the gen w house provided emergy back up and a way to charge the gen batty from eng alt while underway or shore charger when A/C available (by temp combining w house). It turns out I have used the Sw to make sure gen batty was topped off but never needed it for gen starting.
As I said, I'm not a fan of 8Ds and see little benefit to 4Ds. They take up too much real estate for AHs provided and still weigh too much for me to handle easily. I'd rather use a pair of GCs or GP31s but that's just me. GCs and GP31s are usually readily available in most locations... not so with 8D or 4Ds especially in AGMs.
Lots of options and others may have a different preferences.

 

[Circumnavigator]

Trawler Forum should get a commission from Nigel Calder. I think that Boatowner's Mechanical and Electrical Manual is just about the only thing that almost all of us will agree upon.


Jim

 

[SteveK]

I have seen quotes from Nigel, but have not read the book.
But how does Nigel compare to this guy, he seems to know what he is talking about.
https://stevedmarineconsulting.com/wp-content/uploads/2014/03/Large-BatteryBank133_03-1.pdf

 

[Circumnavigator]

I have seen quotes from Nigel, but have not read the book.
But how does Nigel compare to this guy, he seems to know what he is talking about.
https://stevedmarineconsulting.com/wp-content/uploads/2014/03/Large-BatteryBank133_03-1.pdf

Steve is a contributor on TF and the cited piece is well done. I recommend Calder because the book is a very good thing to have on your boat when something happens.


Jim

 

[Bacchus]

Agree N Calder is a good reference to have handy
Two go to resources for TF and online knowledge are Steve DA ( https://stevedmarineconsulting.com/ ) and CMS (Rod Collins from Compass Marine Services https://marinehowto.com/ )
Both are TF Commercial Members here on TF and provide a wealth of knowledge to member willingly and graciously.
Note: CMS is returning from an extended absence for medical reasons but is posting more useful info lately.

 

[jungpeter]

Trawler Forum should get a commission from Nigel Calder. I think that Boatowner's Mechanical and Electrical Manual is just about the only thing that almost all of us will agree upon.


Jim

Hi Jim,

I'm afraid I'm not a member of the Nigel Calder fan club. While I agree his "Boatowner's Mechanical and Electrical Manual" is a valuable resource, I personally believe he provides a fair amount of extraneous information, particularly in the electrical systems section(s) of this manual. Much of which is simply TMI for the average user, and more so for the novice. In particular, does anyone not broken down in Bongo-Bongo land REALLY need to know how to overhaul an alternator? Not bad information, just not really pertinent to the average joe trying to make sense out of marine DC electrical systems. In addition, in my opinion, much of Mr. Calder's manual is focused on monohull cruising sailboats. Again, not bad information, but takes some extrapolation into the world of powerboating for most of us.

For a basic primer, I much prefer the Ample Power Primer. This primer is, unfortunately, out of print, and somewhat out of date. It focuses on flooded lead acid technology, with some discussion of gel technology, but does not discuss more modern battery chemistries. It also includes some information on proprietary (and also no longer available) Ample Power hardware that is OBE, as I believe Ample Power Technology is no longer in business. However, it does provide an excellent description of sound DC electrical systems engineering design, along with some easily understandable electrical schematics for both single- and twin-engine powerboats. All are directly applicable to the Original Poster's (Hydrospud) query.

Should anyone be interested, I have taken the liberty of posting a copy of the Ample Power Primer in the Trawler Forum library.

Regards,

Pete

 

[Circumnavigator]

Hi Jim,

...In particular, does anyone not broken down in Bongo-Bongo land REALLY need to know how to overhaul an alternator? Not bad information, just not really pertinent to the average joe trying to make sense out of marine DC electrical systems....

Well, I actually rebuilt an alternator in Sri Lanka following an earlier edition of the book. Yes, there's a lot of detail, but the average boater can ignore it until he or she really needs it.


I agree that the emphasis is on sailing. The latest edition is 2015, so it's a little behind the times in battery technology, but Amazon doesn't think it's out of print.


Jim

 

[MVDarlin]

Less genny means you need an alternate power source. Go solar with good equipment and lithium house bank.