Help with wiring upgrades. C400

[dhays]

I am a general idiot and not qualified to own a boat with an engine or anything electric. Despite this severe handicap, I am the owner of a 2005 C400 I bought in 2010.

The boat's basic wiring is still in its stock configuration as near as I can tell. The original 4D batteries are no longer holding a charge, to the point that even one night at anchor is enough to severely drain them. Time to replace them. The Alternator is the Hitachi LR180-03C that came with my Yanmar 4JH4HE engine. The battery charger is a Charles 5000 SP series charger. I know what folks think about the Hitachi alternator, but I am just not up to replacing it at this time. The Charles charger as near as I can tell is not terribly good by today's standards either, but again, I don't want to change it now. The original batteries have lasted for 10 years, so while they may be poor, that isn't too bad.

Here is what I want to accomplish.

1. Replace the existing two 4Ds with a single house bank of four 6v batteries, which I have already acquired.
2. Improve the way the system is wired using advice that I have read over the past 5 years by Main Sail and Stu.
3. After #1 and #2 are done, I want to add a separate start battery and echo charger to charge it.
4. Spend as little money as possible.

I have some specific questions, but first this is the way the boat is currently setup.


This is how I think I want to change the system in the first step.


This is how I would like to accomplish the next step. You will notice that the Alternator is connected to Post #1 on the 1/2/Both switch rather than the House Bank positive post. My thought (being the idiot mentioned above) is that this will connect it to the House bank.


If attaching the Alt to the #1 post is a bad move for whatever reason, this would be plan b


OK, some specific questions.
1. What size wire for the interconnecting cables for the 6v house bank batteries? Currently, the connections from the batteries to the switches are 2/0.

2. Can I connect the Alternator to the #1 post on the 1/2/Both switch or does it have to go to the House Bank positive terminal?

3. Have I gotten the basic wiring diagram correct? My idea (not really my idea as these were ideas I got from Maine Sail and Stu) is to keep the 1/2/Both switch on #1. Keep the engine On/Off switch On. This will then always start the engine with the start battery, and the House Bank will handle all the other electrical loads.

If the Start battery should fail, I would turn the engine switch to OFF, and turn the 1/2/Both switch to Both. This would allow the House Bank to start the engine and completely isolate the Start battery.

If the House bank should fail, I would leave the Engine switch ON and turn the 1/2/Both switch to Both. This would allow the Start battery to power VHF and Nav lights.

4. What wire do I connect from the Alt to the House Bank? There is a very tight, organized, and completely inaccessible bundle of wires that run with the Alternator wires to the starter. Basically, there are three small gauge wires connected to the starter on the same post as the 2/0 positive cable coming from the On/Off switch. I assume one of those is from the Alt as the Battery out wire, but any idea how to tell which and what the heck are those other two wires? If anyone has done this on a similar Yanmar I would love some guidance.
This is the back of the alternator.


Again, sorry to take up so much bandwidth with my own ignorance, but any help would be appreciated.

Dave

 

[Maine Sail]

You are on the right track and have a good grasp. The factory wiring makes little to no sense but not unusual for a factory..

Placing the alt on #1 gets you most of the way there but you still lose the voltage drop between #1 and Batt +. Some Hitachi alts also use the top of the T of the plug for voltage sensing and some do it through the B+ (Batt) terminal.

 

[Charles Erwin]

If you do not have them already consider adding fuse(s) to protect the cable to the starter, the charger, the alternator and the distribution panel. The fuse goes near or at the battery.

Charles

 

[dhays]

You are on the right track and have a good grasp. The factory wiring makes little to no sense but not unusual for a factory..

Placing the alt on #1 gets you most of the way there but you still lose the voltage drop between #1 and Batt +. Some Hitachi alts also use the top of the T of the plug for voltage sensing and some do it through the B+ (Batt) terminal.

Thanks. Catalina made a very neat job of the wiring. The wires coming from the Alt were wrapped in table, bundled with other wires into corrugated sleeves, which were then wrapped with more tape with various wires coming in an out of that bundle as it makes it way from the Alt to the starter post and beyond. They then sprayed the whole thing with some type of gray paint. This effectively hides all the wires and all the exposed wires are the same gray color.

I spent a good 2 hours dissecting the Batt+ wire from this bundle. Of course, you can't see it directly, nor reach it with two hands, so it involved the use of an inspection mirror and various long tools. I have no idea how you do this for a living! I am completely sore today.

Anyway, the Batt+ wire is now connected to the #1 post and has a much shorter run to the battery than it did before. I still may get some 4 AWG cable and run it the 5 feet to the battery terminal.

I also am trying to figure out where I am going to put a fuse in the battery cable. I would use a terminal fuse but I don't have the head room in the battery compartment with the GC2s.

Thanks for all your information, I have scoured through it over the years.

Dave

 

[dhays]

Another question, I was originally going to use 2/0 cable for the interconnects on the new bank. After looking at the installation, I am afraid that the 2/0 may be a bit too inflexible to be able to make it all fit.

I was going to use the 2/0 cables because that is what my battery cables are now. However, would it be acceptable to use a smaller cable for the interconnects? Say 1/0 to #2 ?

 

[Maine Sail]

Another question, I was originally going to use 2/0 cable for the interconnects on the new bank. After looking at the installation, I am afraid that the 2/0 may be a bit too inflexible to be able to make it all fit.

I was going to use the 2/0 cables because that is what my battery cables are now. However, would it be acceptable to use a smaller cable for the interconnects? Say 1/0 to #2 ?

Stick with 2/0... If you want to discuss inflexible lets talk 4/0..... 2/0 is overcooked spaghetti compared to 4/0...

 

[dhays]

Stick with 2/0... If you want to discuss inflexible lets talk 4/0..... 2/0 is overcooked spaghetti compared to 4/0...

lol, OK. Thanks I will do that.

Dave

 

[ITMaster]

Four 6 volt batteries

If you got the four 6 volt batteries to fit you were pretty lucky. I tried and they would not fit, missed it by half an inch. Could not believe that Catalina would make that compartment so tight that the two 4 D's would fit and yet the Trojans would not. Someday I plan on cutting & modifying the compartment to allow them to do so since those 6 volt batteries will give me about 30 or more amp hours over what the 4 D's do. They are also easier for me to load one at a time than those ball busting 4 D's are. Not sure I can hump many more of them in my elder years.

 

[dhays]

If you got the four 6 volt batteries to fit you were pretty lucky. I tried and they would not fit, missed it by half an inch. Could not believe that Catalina would make that compartment so tight that the two 4 D's would fit and yet the Trojans would not. Someday I plan on cutting & modifying the compartment to allow them to do so since those 6 volt batteries will give me about 30 or more amp hours over what the 4 D's do. They are also easier for me to load one at a time than those ball busting 4 D's are. Not sure I can hump many more of them in my elder years.

I haven't had a chance to install them yet. I haven't had a free weekend. However, other C400 owners have made them fit and it looks like I will have a 1/2 inch to spare aft and an inch clearance in the forward part of the compartment. It is this weekends project.

Dave

 

[dhays]

terminal help

Just me pestering you all again....

I installed the golf cart batteries today. It went reasonably well except for one problem. On the positive battery bank post, I need to connect; 1/0 interconnect cable, 2/0 cable to the boat, 6 AWG wire from the battery charger, 6 AWG wire from the Alternator, a 10 AWG wire for the voltmeter, and a 10 AWG mystery wire.

On the ground side, I need to connect 2 2/0 ground cables, a 1/0 interconnect cable, and at least for a now a 6 AWG ground for a furnace. Here is what they look like.

You may not be able to tell but the SS nut that is connecting these is just barely holding it all together. This isn't acceptable. For the battery interconnections the cables are connected to the terminals with SS Nylocks with SS lock washers. The Nylocks alone can't grip on these terminals. I need a way to get more room without increasing height as I am pushing the limits of the compartment as it is. If anyone has any suggestions, I would love to hear them.

 

[mitiempo]

Use buses for both positive and negative. There should be only wire on each post - excepting any temp sensors on the negative post.

As far as the mystery wire goes, there should not be an unknown. Trace it.

 

[Maine Sail]

You need a positive and negative busbar.. Also when stacking lugs the highest load always goes first the the lesser loads stacked in order. The small wires never go below a larger wire..

If you used the heavy duty lugs the series/parallel and take offs to the busbar may not fit some brands "posts". Battery makers have shortened these posts to avoid lug stacking and high risk situations but have ignored the fact that even series parallel may be tight with heavy duty lugs...

Oh and every wire connected to that pos post should be fused, preferably within 7" but otherwise as close as you can get....

Here is an example of getting stuff that does not belong on the battery terminal, off the battery terminals. The only things on them are series parallel & take offs plus two temp sensors on the negative.

Here the negative distribution busbar can be seen as well as battery terminal fuses.

The off battery busbars are on the other side of that bulkhead on this 400Ah bank of L-16 batteries.

Another example of off battery busbars and an alternator service disconnect plus volt sensing and a shunt for a battery monitor..

Keep it simple inside the battery box..

An always on bus, switched positive bus and negative distribution bus.

 

[dhays]

Thanks for all the ideas. I was thinking that a bus bar is what I am going to need to go with. The terminals are just big enough to easily handle 2 2/0 heavy duty lugs, a Nyloc and a lock washer. A couple of bus bars would solve my problem.

Finding a solid place to mount them and enough space to do it will be difficult. I still need to find a location for my battery fuse as well. I will see what I can find.

If I did find a spot for a positive busbar, can I run the battery charger and the alternator out to that busbar? I am assuming I can, but I would like to cut down on the number of connections to avoid unnecessary loss.

 

[dhays]

Spent the afternoon on the boat again. I will need to use a bus bar for the ground. I think I can mount it on the starboard side of the compartment towards the aft end. Likely use the Blue Sea 4 post busbar. In the meantime, I connected the two 2/0 ground cables feeding the boat to a short cable with a SS bolt. The short cable is connected to the negative terminal.

I spent a lot of time figuring out how much vertical clearance I have over that positive terminal. I think I might have enough room for a terminal fuse block. I can use a double and connect the alt wire to to one fuse and the primary positive cable to the other. I may have to cut the posts a bit on the fuse block to make it fit.

I did discover the brown mystery wire, as I suspected it goes to the bilge pump.

 

[peter_ms]

Just me pestering you all again.... I installed the golf cart batteries today. It went reasonably well except for one problem. On the positive battery bank post, I need to connect; 1/0 interconnect cable, 2/0 cable to the boat, 6 AWG wire from the battery charger, 6 AWG wire from the Alternator, a 10 AWG wire for the voltmeter, and a 10 AWG mystery wire. On the ground side, I need to connect 2 2/0 ground cables, a 1/0 interconnect cable, and at least for a now a 6 AWG ground for a furnace. Here is what they look like. You may not be able to tell but the SS nut that is connecting these is just barely holding it all together. This isn't acceptable. For the battery interconnections the cables are connected to the terminals with SS Nylocks with SS lock washers. The Nylocks alone can't grip on these terminals. I need a way to get more room without increasing height as I am pushing the limits of the compartment as it is. If anyone has any suggestions, I would love to hear them.

Try something like this
http://www.ezacdc.com/boat-wiring-products/bus-bars/compact-marine-electrical-bus-bar/

 

[dlochner]

Maine Sail has photos of positive bus bars on his website. Here's a link to one of them.

http://www.pbase.com/mainecruising/image/140421725

 

[dhays]

Thanks for the links guys.

I know how to setup a busbar for the ground, the issue is making it fit in the space I have available. The boat is only 10 years old, but when it was built it didn't have a busbar for the ground, even though they used two separate 2/0 cables for the ground. The boat had two 4D batteries. One of the ground cables connected the Batt #1 neg terminal to a busbar behind the electrical panel, about a 12 foot run. Another 2/0 cable connected Batt #2 to the engine ground, about a 6 foot run. There was a 2/0 cable connecting the two negative terminals of the batteries. No fuses in the positive lines either.

The issue is that the battery compartment is very tight. Going with the 4 GC2s I got myself a couple inches along one side and that is where I will have to put a negative busbar. Assuming I can get my hand in behind the fiberglass wall of the compartment to put washers and nuts on the end of the bolts to mount it. It is too thin to for screws to hold.

 

[dhays]

Hi guys,

Today I did some more finishing touches on my battery changes. I didn't get any photos today, frankly my back was toast and I was too tired to think about it.

As you may recall, I took out the 2 4D batteries that were in the battery compartment and replaced them with 4 6v Golf cart batteries I bought at Costco. These are the "Interstate GC2-RD-UTL 6-Volt Golf Car Battery replacement battery" with a Costco label on them. They are all connected as one bank and wired to the #1 post on the Battery Switch.

I had run the Alternator directly to the same post on the battery switch a few weeks ago but today I put a new 6AWG wire from the Alternator to the positive battery post. The stock configuration has the Alt out going to the starter. Current travels from there along the 2/0 cables to the engine switch, then to the 1/2/Off switch, then to the batteries. The total wire run from the Alt to the battery now is about the same and is all 6 awg instead of the combined 4AWG and 2/0 it was before, but there aren't any connections so I think the voltage drop to the battery will be very low. As I calculate it, the drop from the Alt to the battery will only be 2% max at the Alternators max output of 80amps. Since the Hitachi Alternator temperature adjusts, it doesn't put out those 80 amps very much, only when it is cold which would be just after engine start. It was a two person job getting the new Alternator wire from the engine compartment to the battery compartment. That wire run is very tight.

I also finished putting fuses on the battery. Initially I was going to use ANL fuses but I couldn't find a good place to mount them. I ended up using the Blue Sea terminal fuse block. My biggest concern was the height they add to an already vertically challenged space. Turns out they were too tall for the space as I expected but I was able to cut about a 1/4 off the posts of the fuse terminal and they fit in the compartment (barely). Since my battery interconnect cables were 1/0 I used a 250amp fuse for those and a 100amp fuse for the 6 AWG alternator wire. I also attached the 6 AWG charger wire to this same fuse even though it has its own inline fuse in the wire. One of the advantages of this is that I had room now to make all the cable attachments I needed without running out of room on the posts. It also now is a lot safer with being fused and meets current requirements.

The final step was connecting the two 2/0 ground cables, and the ground for my furnace to a bus bar. The bus bar isn't mounted to the side of the compartment yet, that is another project for when my back recovers. It is hard to bend over and work down in that battery compartment for me. I also need to improve how the batteries are secured in the compartment so they can't shift at all.

Anyway, I am happy with how it has turned out although it was a lot more work than I initially would have thought. The next phase of the project will be to install a start battery in the compartment under the sole next to the battery compartment and connect an echo charger to it. I don't think it will be as difficult IF I can use the existing 2/0 positive cable that used to connect battery #2 to the #2 post on the 1/2/Off switch. I would like to use it to connect the start battery to the Engine On/Off battery switch. It will just be whether I can make it reach or not. If I have to pull it out and run another one, it will be a major pain.