Doing Better Battery Wiring

[GeneM]

Any comments on my plan to change battery wiring? See the picture. I'm very curious if it's better or worse to tie the generator into both banks.

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[Suijin]

Your image is too small to read the writing when it's blown up. Would probably help to post a higher resolution picture.

[GeneM]

Maybe splitting to two images is better.

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[Suijin]

I assume bow battery is for a windlass. Why not add it to the house bank and just run the windlass off the house bank? Or is it physically located at the bow?

My boat had a dedicated windlass battery when I bought it, that would only charge off shore power. When I replaced batteries I nixed it and run the windlass off the house bank with no ill effects.

[smattie]

I'm new to cruising, but owned a company that built very high end motor homes for 28 years. I see these as way more useful (you can go almost anywhere in the world!). One of the huge issues with land yachts is the battery systems. Most high end units are 24V system using inverters with solar panels, generators with chargers, and an alternator to keep the batteries charged. In looking at your diagram it appears three batteries are all separated. I understand keeping the engine start separated, but that can be done with a battery separator and seeing you use different batteries, you can do the same betwe. This also keeps from overloading your charging source. You can install an automatic (low voltage) disconnect that will disconnect the start battery from the circuitry so you'll never have to worry about killing that one (or for piece of mind, just keep it connected to only the charging system with the separator.) A battery combiner is also a good item as well. Blue Sea sells some really good stuff. We used Blue Sea for almost all our electrical systems. Check it out - Google "battery combiner" and "battery separator". I sure would like to know if your circuit is normal as it appears everything is somewhat separated.

[GeneM]

Thanks again. My bow battery actually is connected to the house bank, but it goes through a split-charge relay. So, it isolates on draw-down, but charges when a charge is available.

I know there are better ways to set up the batteries. Thanks for some details I can explore. I am planning to hire someone who can check what I have and maybe do a redesign. The good news is the house bank is charging well now that I added the neg jumper and moved the stbd battery negative to the second neg.



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[Ahmet Erkan]

Hello Gene,
I would like to help but before attempting to design anything we should establish a few things and at least label all the terminals on the components we are going to interconnect. For example the box marked charger does not seem to have a negative terminal. No short circuit protection for the wiring is a major concern. Not sure if it is desired for both engines/alternators to charge their own discrete starter batteries and be completely independent from one another for redundancy. The type of batteries, capacities and charging requirements are also unknown. Link isolator?
Again, I will be glad to sketch a suggested wiring diagram and select wire sizes etc that does what you want and is safe but the existing components you would like to use and the functionality you want implemented needs to be described.
Good luck and please don't take electrical design lightly. Some practices may be forgiving but others could lead to grave problems. (pun intended)
Cheers mate.
Ahmet

[Cadence]

I'm sorry, I can not make much sense out of your schematic. Just as a suggestion. Everyone I've seen trying to charge multiple banks have only looked at the charge not the draw aspect. Basically paralleling them as one big bank. For what it is worth or isn't.

[ramblinrod]

Originally Posted by GeneM

Maybe splitting to two images is better.

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There are some serious issues with your drawing.

For example, I can't figure out what the "Link Solenoid" is supposed to be doing, based on the drawing.

Additionally, all battery, charger, and load negative terminals should be joined in one spot, (that should also be connected to a grounding and bonding system).

I do think it wise to get a pro to go over your system needs, prepare a proper diagram, and then actually wire it that way.

[mrm]

Take that comment with a grain of salt..
https://xkcd.com/730/ but, seeing your initial drawing, couldn't resist.

More seriously, unless you are planning to be a long way from anywhere and redundancy is your top priority, I think that the general agreement is to wire house batteries as a single bank. This is certainly easier on batteries.

[GeneM]

Ahmed

Thanks for the offer, I think I will hire a pro to do a major redesign.

The charger does not have a 12v negative, just positives. I think this was common a while back. On circuit protection, I don't see breakers on anything but the house load items. The systems are currently isolated, but the two banks have a jumper on the negatives. The link solenoid combines the positives on both banks so cross starting is possible. The batteries are lead-acid wet cells - 4D's.

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[mitiempo]

Originally Posted by GeneM

Ahmed

Thanks for the offer, I think I will hire a pro to do a major redesign.

The charger does not have a 12v negative, just positives. I think this was common a while back.

Without a negative connection the circuit is incomplete. The charger will not work without a negative connection - nor will any DC item work without both a positive and negative.

Yes, hire a pro.

[jeepbluetj]

Yup. The charger has negative leads for sure. A pro may be a good idea.

[GeneM]

Thanks all again. I checked the charger manual and, yes, there is a negative. I missed it because it was deep in a harness.

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[Gamechanger]

While the wiring arrangement in your drawing may well work, I'd propose simplifying it. For example, install a single buss for all of your negatives to tie into. Tie your house bank batteries together as one then tie everything else in accordingly.
I've never been a fan of isolators since they often cause more confusion than good.