DC Electrical Upgrade

[Jammin']

I'm a little nervous coming out electrically here, so to speak, so go easy on me. I am planning a modest upgrade to our battery and charging system. I have attached a diagram that shows approximately where things are and will be located in the engine room of our 43DC.

The inverter set up is a little different than most. I have one duplex outlet next to the refrigerator. To use the inverter, you physically plug in what you want to use. This system is fine with me. We need nothing more complicated. It is currently used for the refrigerator while under way, a coffee pot, or a microwave, or a toaster oven. It was previously hooked up to the single 8D for the thruster and windlass. We promptly fried that battery and the alternator on the port side on our trip up here. Not enough capacity and no way to monitor it. Eventually we may go to a 12 volt refrigerator to reduce the load on the inverter.

In the illustrated set-up, we would have one AGM house bank with a modest capacity of 440ah and a battery monitor to keep track of usage. All DC loads except the thruster (well, half of the thruster as it combines with this bank for 24 volts), windlass and starboard starter would be hooked to this bank. This bank would be charged off the new 120 amp externally regulated Balmer alternator, derated by 15% so as not to overload the single 1/2" V-belt, and off the 60 amp leg of the Skylla charger. The alternator would be spinning at approximately 3150 rpm at our 1400 rpm cruise engine speed.

The battery to aft would be a dedicated FLA starting battery for the starboard engine only and charged by the starboard engine alternator and the 3 amp leg off the Skylla charger. We have a combining solenoid for the starting and house banks should we draw down the house bank too far to start the port engine.

The thruster/windlass battery would be an AGM 4D. AGM because it is really difficult to get to for maintenance. The minimum capacity required for the thruster is listed as 150ah in the manual. This battery would be charged off the port engine 120 amp alternator and off one leg of the existing Statpower 40 amp charger.

For the next couple of years, we'll be fixing up the boat for our intended usage of cruising to Florida and the Bahamas when we retire. Maybe farther. Maybe further. Any suggestions on how to make this system better and/or simpler?

 

[Pascal]

When it comes to batteries I like redundancy.

A separate charging battery for each engine and genset, charged by their respective alternator and a charger. Since your mains appear to be 12v like mines, it s pretty easy.

I also like house to be separate from inverter, again for redundancy reasons. same for the thruster. Nowadays with LEDs you don’t need as big a house bank as you did in the past making it easier to set up. You could have a 24v Charger for the house and thruster bank. Inverter banks are usually charged with the inverter. All it takes is a 24v alternator on one of the mains to have a back up in case you loose the generator.

 

[Boatsb]

First question. Is it a marine inverter?

Second question why 4 x 6 volt batteries? Are they start pr deep cycle by the way?

Third question. Why the 1+1 charger and not the 3 bank ip44?

Fourth question. Would you like to talk to a victron distributor and go over the design?

Theres a few options you may want to consider as an alternative design.

 

[Reefgeorge]

I was cooking batteries when the boat was new so I made some changes/upgrades. That included temp sensors for the batteries, better battery ventilation, isolating charging to dedicated banks and a Balmar regulator on each alternator. The Balmar regulators are really slick with many programming options. Then you leave your shore chargers off when running and your batteries get a proper multistage charging profile with a float charge during extended runs. The problem for me is that they don't last very long and I have replaced them both almost yearly. I don't know if its my set up or they are inherently unreliable. YMMV.

George

 

[Dazed338]

Glad I only have a 31C, PO already added a Pro sport 20 Plus charger so added a House bank. Both engines have their own starting batteries, I added a Bep modular Switch set up. Also currently have a Aims inverter with a auto transfer switch, mostly for Fridge. At this stage a larger 120v Fridge / Freezer is in the plans with smaller being beverage only. I would probably through an isolator use both starting batteries for the thrusters, since they would be somewhat quick loads like starting and come back to full quicker. My initial plan was for extended time out on the Great Lakes, and now at some point the Great Loop. Didn't see generator in the diagram, adds yet another for of charging to keep batteries up. My plan now includes easialy adding solar as well when the time comes. But in the whole scheme of things, engine batteries for the engines, and the house bank for house related power needs.

 

[Jammin']

I have an 8K Westerbeke generator, but I didn't picture it because it isn't involved in the upgrade.

Another scenario I've considered is making the thruster bank larger and hooking the inverter to it. Adding another shunt would allow it to be monitored by the SG200 as well. It's the scenario that makes the most sense in my mind, but I've been advised by someone who knows far more than me to just have one house bank. I've illustrated that set up below.

 

[Pascal]

Thrusters cause serious voltage drop when they run which will trigger the low voltage cut out on the inverter.

And if that bank is also used for the windlass, after being in the hook generator off, using that bank for the inverter may cause it to be low when raising anchor.

Having one house bank is good but having a dedicated inverter bank is even better. For instance do you want your bilge pumps performance and the visibility of your anchor light affected by your inverter running your fridge? I don’t

 

[Jammin']

I see what you're saying. What I'm running up against is where to put the batteries. I've got these relatively large spaces outboard of the engines and they clearly used to be batteries there, but I love that space for working. It's part of the reason I didn't want V8's too. I'll have to think about that. I think you're right.

 

[SKYCHENEY]

I use my house bank as my inverter bank. I also run the windlass off of that bank. And I have never had a low voltage issue like Pascal is describing. My thought is that if you have proper wire sizes and the right batteries, you won't have those issues. Of course, higher voltage means less amp draw so my 32v bank makes a difference there compared to a 12v or 24v bank.

Also, I notice that the questions Scott asked in post #3 have not been addressed:

"First question. Is it a marine inverter?

Second question why 4 x 6 volt batteries? Are they start pr deep cycle by the way?

Third question. Why the 1+1 charger and not the 3 bank ip44? "

 

[Dazed338]

https://www.youtube.com/watch?v=tdur_Ln-9cE

Plenty of videos and great information.

 

[Boatsb]

I didn't look through the whole library but they seem to have a bunch of info.

Look at the system as a system not as a price sensitive choice was a big take on the video.

 

[Jammin']

I'm still working on my electrical upgrade and I have a long way to go. While I had the generator battery and generator muffler out and the forward battery bank vacant it gave me access to an area that is normally very difficult to get to, so I thought I'd clean it up and paint it, but it didn't make sense to stop short of cleaning all the bilges. That was a couple of weekends right there. The generator exhaust had been leaking so some of the wood had gotten punky and that had to be fixed prior to painting.

I needed to mount a busbar for the negatives so I could install a battery monitor shunt. The cooling lines for the forward and salon AC units were run haphazardly and the tubing was clear hardware store stuff that had hardened. I replaced all that with Trident 132 and rerouted it out of the way. There was a comical succession of fittings and hoses pieced together on one of the bilge pump discharges that also handled one of the condensate lines that got cleaned up. Lots of wiring splices and cords that got removed and rerouted. Since I am increasing the size of my battery charger, I'm replacing the existing 8 gauge wire with 6 gauge and installing the temperature compensation sensor. There were no fuses at the batteries so that's happening. Today I installed new LED engine room lights on the port and forward perimeters of the engine room. While I was doing lighting I pulled out the 120 volt lighting in the galley and made it all 12 volt LED. I finished that on Saturday.



To make room for the Victron Skylla-IP44 charger I bought, I had to remove my large accumulator tank and re-plumb in a mini tank. When I removed the water filters, I found rot damage below. I dug all that out and I've saturated it with epoxy and laid the fist layer of cloth. I had hoped to get more of that done this weekend, but installing and wiring the lights went tediously slow. As long as I have the area where the charger is going partially apart, it makes sense to pull everything out and clean up that area. I am going to prepare the area for a second battery charger in the future. At least I will have nice lighting in which to do it.

I am working my way around. The forward batteries should be ready to go in soon and then I can finish reassembling and servicing the generator. That will feel like a milestone. Next I need to start working on the aft new battery bank and the alternator and external regulator installation. I have made the new battery tray and I just picked up another shunt so I can start planning out the wiring.

Oh, and the refrigerator just quit.

The road goes on forever and the party never ends.

 

[brettportzer]

That is great - been following your projects!

Any pics of the cleaned up bilges to keep me going while I work on ours?

 

[Jammin']

I'll get to those pictures when more is done. Does anyone know if there is a commercially available serpentine engine pulley available for a 671? Or even a double vee.

 

[Jammin']

I'm looking at my overall charging rates for both the alternator and the battery charger. When I install the new alternator and external regulator, it will be charging two AGM battery banks with a rated capacity of 440 ah each. At the present time I will have one 60 amp battery charger with an eye toward adding a second one in the future. Even with 120 amps of battery charging capability from two chargers, it will only amount to 13.6% of battery capacity. The constant current charging time to reach the end the bulk charging period will still take quite a while. As I think I understand it, the absorption charging period of constant voltage and declining amperage, which continues until the batteries are deemed fully charged when the charge acceptance rate drops to .5%-.75% of the rated amp hour capacity, will be an impractically long time to run the generator when away from shore power. It would take even longer with the engines running with a 120 amp alternator de-rated to say 90 amps depending on temperature. It seems like if we were to be anchoring out for any extended periods of time, the only practical way to fully charge the batteries would be to add some solar component.

All of this would seem not to be an issue if the engines are running for long periods of time every day and/or the boat is hooked up to shore power at night.

Is the end of the bulk charging period determined by the voltage that the battery attains or by the reduction of the charge acceptance rate?

 

[Jammin']

I guess I'll have to go back to the Nigel Calder book for that answer. I get distracted easily in the engine room. I keep following and pulling stray wires. When I see electrical tape I want to know what's under it, like the wire to the hot water heater below that popped out from the tape just now.

 

[Captain Ralph]

I'll get to those pictures when more is done. Does anyone know if there is a commercially available serpentine engine pulley available for a 671? Or even a double vee.

This Detroit Part MAY help
https://www.powerlinecomponents.com/detroit-diesel/23508421/pulley
It is a 10 groove pulley with a 7.5 inch diameter. You may need a longer crank bolt.
Also, Vintage parts ph# 877-846-8243 usually has them on the shelf for bus conversions.

 

[Jammin']

It took a lot to make the space for these chargers, but I'm pleased with how it's coming together, albeit slowly.

 

[12V71]

My 3 Thoughts
1. would not want all the electrical systems tied to each other.
2. find, fix, and or replace problems (you showed a mess on one, Hot water looks like it needs to be completely rewired)
3. more practical research: cost, longevity, reliability

 

[Jammin']

Also, I notice that the questions Scott asked in post #3 have not been addressed:

"First question. Is it a marine inverter?

Second question why 4 x 6 volt batteries? Are they start pr deep cycle by the way?

Third question. Why the 1+1 charger and not the 3 bank ip44? "

It is not a marine inverter. The inverter is mainly for the microwave and coffee pot, now that I have a 12 volt refrigerator.

The reason for four 6 volt batteries (deep cycle AGM) is to increase the capacity of a battery bank that is in a location that is almost impossible to get to and the 6 volt batteries are a more manageable size and weight. That battery bank will have the inverter, windlass, DC refrigerator and half of the bow thruster on it and is monitored by a Balmer SG200.

I have installed two 60 amp Skylla-IP44's, both the 1+1 charger and 3 bank charger. One handles the new 4 x 6 volt bank and one handles the other two banks of one 8D each. The 8D's are in a more accessible location. One 8D is a sealed FLA that is for starboard start as well as currently having the bilge pumps wired to it. In 1-1/2 years, a bilge pump has yet to cycle. The other 8D is a Lifeline AGM with the rest of the ships electrical functions on it including lighting, waste system, port start and the other half of the bow thruster. The latter is also monitored by an SG200. I installed a combiner for these two batteries.

The generator has it's own starting battery that is charged by the generator and a small multistep charger when on shore power.