Looking for insight on Electrical upgrade

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Eddie W

Veteran Member
Joined
Sep 19, 2019
Messages
63
Location
usa
Vessel Name
Tidal Holm
Vessel Make
Mainship 34 MK1 1982
Soon I will be attacking my boats wiring. Plans are to inspect, repair and/or replace all the factory wiring and to replace all the wiring that has been added over the years. My best friend is a retired Navy Guy (electronic Genius) who will act as my mentor and inspector, we co-owned a sailboat several years ago and did a complete refit including all the electrical , so this will not be our first job together .

I currently have a ProMariner 1240P charger which is adequate for what I have on the boat now, but plan to do some upgrades down the road. As many know the charger has three banks and I am currently only using two. I have a couple questions and any insight would be appreciated, from what I learn here, I can bounce it off my friend as we set forth a plan.

Do you have more than one charger onboard? I like the Promariner I have and would like to add a second 1240P or even a 1260P.

Currently batteries are located in four different spots, bow thruster and anchor windlass batteries are right next to the bow thruster and windlass and I plan on keeping them there, I like the shorter run on the cables and will upgrade them to one size larger than needed. Your thoughts on this?

House and start batteries are in 3 separate locations, I will consolidate these into hopefully one possibly two locations. House and start batteries consist of 6 batteries, two group 24 12v for engine start and Gen Start, four 6 volt golf cart batteries for house and inverter bank. Battery boxes and hold downs are in the plans and if I set them up in two locations, when I add more batteries for house, I will be ahead of the game. Any thoughts?

Currently the boat has 430 amp hours for house, all the batteries are one to two years old, so by the time I am ready to upgrade the house bank ( 1 to 2 years) I will probably be replacing what I have. Our plans are to do the loop in 2021, using this year to get the boat and us ready. And we will spend some time in the Bahamas when we finish the loop, thats when we want to have our house bank upgraded so we can spend more time on the hook. We have an Onan 8kw genset and not quite sure yet about the charging capacity of the Perkins.
 
We have 2 4D starting batteries, 4 6V golf cart batteries for the house and 1 AGM for the stern thruster. The windlass is wired off the port start battery. We have a Promariner 1260P charger that charges the 2 start batteries and the house bank. I have a Promariner 1215P that is located by the stern thruster and just charges the thruster battery. The small charger seems to work fine for the thruster battery and was fairly cheap and having it close to the battery keeps the cable size down. I also have oversized cables so we get good voltage. The cost difference is negligible and in the scheme of things doesn’t even count. I try to make good connections and use a copper paste and adhesive heat shrink on them to keep them from corroding.
 
If you are starting from scratch, this is what I would do:

Tie the bow thruster and windlass batteries together as one bank and charge them with one leg of the Promariner. Read Yandina.com's project notes on installing a remote battery: How to add a remote battery bank on a boat. Wire it like it says with a combiner or ACR to let the engine alternator charge the two batteries when the combiner/ACR ties the house to the remote batteries. The article shows the start battery being the power source because 99% of boats are wired with the alternator feeding the start battery, but since you are rewiring from scratch the house battery should be charged from the alternator. See below for why.

Two Group 24s as a starting battery is a little weird. I would replace them with one Group 31. Then run the alternator output directly to the house bank which should be in one location. Then use another ACR or combiner to charge the starting batteries from the alternator (or any other source feeding the house bank, like the Promariner).

I would set up a separate battery for the genset for redundancy. Charge it from one of the outputs of the Promariner. If you really want to go all out install another ACR/combiner to charge the genset battery from the starting battery and the propulsion alternator output. But genset batteries rarely need much charging and when you are running the genset you will be charging it from the Promariner output.

Then finally use the third output of the Promariner to charge the house bank.

So why set them up this way:

The main issue is having the propulsion engine alternator charge the house batteries first and then indirectly charge the starting and bow and windlass batteries through ACR/combiners. Why? Because house battery charging is the biggest load on a boat so you want them charged directly.

The starting batteries get charged by current from the propulsion alternator through the ACR/combiner when the voltage gets up to 13.2 or so. The same is true for current from the Promariner to the house bank.

So those are my thoughts. Let the arrows fly.

David
 
Here is an marine electrical seminar in - ready for this - 30 parts, some short, some longer. But you will be ahead of the game, if you make it through all 30 of them. I link Jeff Cote all the time:

 
I do have two chargers, but the second is only a backup. The guiding philosophy of this boat is to permit reliable operation in desolate locations where necessary parts and repair skills may be scarce. As a result, there is lots of redundancy, and relative simplicity. For example, the hull is solid below the waterline, recognizing that through hull penetrations, if not performed correctly, could ultimately lead to hull delamination and failure.

The battery configuration reflects this as well -- all lead acid and only two banks (starting and house). Despite its length, bow thruster and windlass (and stern windlass too) are powered from those mid-ship (engine room) batteries, although the thrusters and windlass are 24 volt (combining house and starting banks in series -- no common ground). Everything else is 12 volts (because it is easier to find a 12 volt pump-or anything else - in the middle of no where than the 24 volt version).
 
keep the comments coming, the more info the better.
 
Yes, do take in the PYS videos above.
 
David has good advice in his post above. I would do one thing differently than most. For AC battery chargers, I tend to recommend having one for each battery bank, sized appropriately for the bank. The reason is that most chargers have outputs for multiple banks, but only regulate for one bank. Having separate chargers means each is regulating its output correctly for the bank it is charging. If you already have a larger inverter on board, you can run the smaller chargers through the inverter while the house bank is charged by the alternator, and all the banks will be better regulated than using an ACR or similar combiner.
 
Our setup is somewhat like DavidM's suggestion. All g31 AGM's, except one g24 FLA for the genset. In four different locations - four for house, two for main start (and the Cummins grid heaters), two for bow thruster and windlass, and one for stern thruster. All big cables are 2/0 with power lugs.

Main engine alternator (regulated by Balmar MC-614) and inverter/charger both charge to the house bank. Batt voltage sensed from the house bank. Start and thruster/windlass banks are connected for charging by ACR's. House and start can be combined by a switch in an emergency.

Works like a charm.
 
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We relegated all starting duties to a single Group 31 AGM (ignore the 8D label) and find it more than adequate for the Lehmans and genset. We don’t have a bow thruster. Another difference from the diagram: we have a pair of 4/0 cables feeding the main circuit panel from the fuse bus (which are at opposite ends of the engine room) to minimize voltage drop when high-amperage loads, like the windlass, are operating.

The Balmar Duo Charger keeps both banks topped off while underway and the simple on-off switch allows starting from either bank. The remote battery switches are inches away from both banks and can be operated remotely from the saloon. The Balmar remote regulators are set to the charging profile of the house bank AGMs, which also works for the profile of the Group 31 AGM.
 

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For most internal wiring I have found purchasing a coil , 600 or 1,000 ft of # 10 tinned wire to be simple .

A coil of white , a coil of black ,, shrink tubing in what ever color is current where you are located , and Anchor terminal ends with an Anchor crimp tool.

Amazing how fast a 35 - 45 ft boat eats up the coils.
 
David has good advice in his post above. I would do one thing differently than most. For AC battery chargers, I tend to recommend having one for each battery bank, sized appropriately for the bank. The reason is that most chargers have outputs for multiple banks, but only regulate for one bank. Having separate chargers means each is regulating its output correctly for the bank it is charging. If you already have a larger inverter on board, you can run the smaller chargers through the inverter while the house bank is charged by the alternator, and all the banks will be better regulated than using an ACR or similar combiner.

I will most likely use my pro mariner 1240P to keep start batteries and batteries for windlass and thruster in a maintenance/float state while in a marina. I will purchase a 1260p to handle the house bank. When I upgrade the house bank, it will be AGM. House will be used to extend my time at anchor, not so much to handle a lot of daily loads. Fridge, Lights, coffee maker are about all I will require, any heavy loads I can run while underway or run the genset for an hour a day.
 
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