Electrical systems 101

Electronics was not my strong suite in high school and I managed to avoid it throughout university. However I am the new owner of a 1985 Kadey Krogen 42 and find myself somewhat overwhelmed with the electrical system and it seems to be a steep learning curve.

First off, the previous owner was quite savvy concerning electronics. Everything seems to be working very well. The wiring in the helm has been completely redone and is very tidy and handsome. Others have remarked on what a wonderful job he did. Anyways I need some direction on how to upgrade my knowledge. If someone has a particular book that is helpful at the novice level, but at the same time thorough, please provide me the title. The following systems are on the boat:

Starting bank: (2) Trojan 105 6V wet
House bank (10) Trojan 105 6V wet
Shore Power: (2) 30A 125V
Freedom Marine 20 100 amp charger for house and start, Echo charger or Victron Centaur 12-40 for thruster bank, and ProSport 6 for generator start
Generator: Entec West 4200W, 115VAC, diesel fired, fresh water cooled, water lift muffler system 24 hours
Heart Interface, Link 2000
1 X Balmar Digital Duo charge
1 X Balmar Max Charge MC-612 multi stage marine regulator.
Freedom Marine 20 100 amp charger.
Engine alternator: Amptech S125E, single belt.

The mechanic I hired on survey remarked that the charging and wiring systems had been done well and he particularly drew my attention to the two Balmar gadgets, saying this was a very good setup.

I am checking the fluid levels in the batteries and adding distilled water as required with one of those battery fillers. I also tested all the cells in all the Trojan batteries with a battery hydrometer. One cell in each of two batteries in the house bank were poor based on the hydrometer. We have never yet run out of power during 2 days on the hook and everything seems fine based on my systems check with the Link monitor. However the batteries for the house bank are at least 6 years old now.

The generator runs well and has only 30 hours on it.

I find that the charging system runs for quite a while when I plug into shore power, even after a 4 hour run with the main engine. Is this normal?

I apologize in advance if this has been covered in other posts, however from what I have read, there are different views out there on this subject.

Jim

Yes, sounds strange that batteries should charge on shorepower after a run. Two bad cells are enough and can accelerate the death of others by overcharging. If it were me, I would take those batteries with the bad cells out of service. I would not replace them with new 105's but either reduce my house bank to 8 or use the two from the starting bank so as not to mix new and old.

If the house bank is discharged to the 50% level then 4 hours on the engine may really not be enough to bring them back to full charge. Then when plugged in to shore power the battery charger must finish the job. Even at less than a 50% discharge 4 hours may not be enough to really finish the job.

I'm not ignoring, maybe I am a bit, the fact that you have two possible questionable cells but with a 10 x 105 trojan you have effectively a 1,000 or 1,100 amp hr bank. At the 50% [500A hr] level that means the alternator would have to run for 4 hour minimum at straight arithmetic calculations. Unfortunately that won't work. The recharge rate is not that simple.

The alternator will unlikely put out 125A continuously and it may in fact actually be turned down at the regulator to a lower level of output to protect it.

Many alternators, when they get hot drop output by up to 25%. Perfectly normal unless built for that.

The regulator likely has a battery temp. sensor attached and if the temp rises, as it may well do, the regulator will back the alternator off to protect the batteries.

The batteries themselves, as they approach the 80% or so recharge level, will accept less current as their own voltage rises.

You also have a/several bleed offs in the form of Echochargers which will bleed off a portion of the alternator and also the charger output to bring their associated batteries up to snuff.

Your boat has standing loads including lights, pumps, electronics, anything that runs while the boat runs. All that comes of the supposed 125A alternator output so what actually gets to the battery is less than you might think.

So a straight line arithmetic calculation will not work.

You may be able to improve the questionable battery cells by running an equalization cycle or two. This raises the battery voltage to up to 16V depending upon the charger mfgr. for a period of time.

While doing this though ALL, and I mean ALL equipment must be turned off as some stuff can be damaged by the high voltage. The batteries should have had this done periodically to realize all the life available. At 6 years unless the batteries have been abused you should get more life out of them hopefully.

If the equalizing doesn't seem to help then you may be better served by simply removing the questioable units, swapping in the engine start batteries assuming they are the same age and installing new engine start batteries as suggested by Brooksie. Or simply do with a slightly smaller house bank.

Also look up and read this site:

SmartGauge Electronics - Interconnecting multiple batteries to form one larger bank

You have too many batteries for solution #4 to work. #3 would be the best connection setup. Read the article and it explains why. Compare to your battery connection setup. And how the batteries are connected does make a difference in their life.

And consider a book. Nigel Calders Boatowners Mechanical and Electrical manual
http://www.amazon.com/Boatowners-Mechanical-Electrical-Manual-Essential/dp/0071432388

Or from your local chandlery.

Good luck

At replacement time I would prefer real start batts , if the Trojan 105s are deep cycle.

You need an SOC meter to understand what is happening.

SOC is state of charge , about $200 .

Not sure what "quite a while" is, but the chargers I've used typically indicate "charging" as soon as you power them with AC. They'll take a while to step down to a float charge. It seems like a pre-programmed cycle, happens even if they were fully charged just prior, like if you turned off the breaker, then back on again a few minutes later.

Not quite on thread but is 101 type question.

My new to me trawler is well equipped and the PO was an electrical engineer, so all systems well arranged, however there are no wiring diagrams for any systems. I have searched the web for some type of twin engine, generator, battery banks generic diagram to just as a starting point, without success. Any such animal exist or just get colored pencils and start drawing ?

Thanks all for your input, and I will review the article and get a hold of that book, thanks. The previous owner replaced the Sub Zero AC side-by-side units with Novakool DC ones. The battery banks were originally set up for the AC fridges, hence the very large banks. I need to get a better way of ventilating the Novakool units, although they have extra fans installed. I'm also looking at improving the insulation on the doors. In the warm weather these units run a lot.

The house banks are broken up into one of 6 batteries and one of 4 batteries. I'm having a little difficulty interpreting the Link 2000 display and find the manual for it a little cryptic, but I don't believe I have discharged the units to 50%. The monitor indicates never less than 12 volts when off charge on one battery bank and 12.5 volts on the other. Now by "other" I'm uncertain if the second one is the starter battery or the second house bank. As mentioned the previous owner was pretty pleased with the setup and would often go 3 days without using the genny. The genny only had 26 hours on it when I purchased the vessel and he installed it at least a couple of years ago.

I will check those batteries out again. It seems like good advice to take them out of service, as long as I can figure out how to do that without impacting the setup. Also might consider putting in the starter batteries into the system and putting in new starter batteries.

Thanks for your advice and I will continue to check in with more questions.

Jim

sea hag said:

Any such animal exist or just get colored pencils and start drawing ?

Click to expand...

I'm not sure I'd be able to use a complete wiring diagram for a boat this size.

Usually you're working on one system at a time, so that's the only one you care about. Having a rough diagram for each system showing where things are terminated and what color wires are used would be a big help. So is labeling the terminals, switches, fuses, etc.

My boat was professionally re-wired a number of years ago, and everything is pretty clean, at least what was installed back then. The biggest problem I have is that everything goes into big bundles of wires, making it hard to figure out where any one wire goes from there. I've gone through a lot of wire ties, breaking apart bundles, finding the one wire I want, then putting them back together neatly. Sometimes I add labels along the way for future reference.

JDCAVE said:

The previous owner replaced the Sub Zero AC side-by-side units with Novakool DC ones. I need to get a better way of ventilating the Novakool units, although they have extra fans installed. I'm also looking at improving the insulation on the doors. In the warm weather these units run a lot.

The monitor indicates never less than 12 volts when off charge on one battery bank and 12.5 volts on the other. Now by "other" I'm uncertain if the second one is the starter battery or the second house bank.
Jim

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I have Novakool in my boat and have found it a great unit. I replaced a much larger Norcold so was able to add 6 more inches of reflective foam to all sides of it. The door is the weak link for sure. As for venting, I originally thought air was going to flow in at the toe space and out a grill I installed just under the counter edge but in the end, I installed a vent at the back of the counter and I seem to get a LOT more heat out that way.

12.5 volts at rest OK but 12 volts at rest is low. At rest means fully charged, then no draw for 5-8 hrs or the "surface charge" drawn off with a high load for several seconds. I'm quite sure, if you have bad cells, you need to remove those batteries b/4 the remainder of the banks are harmed, replace them with the 105's from the starting bank hoping they are the same age then replace those. A starting battery would be better but don't install 2-12 batteries and wire them in parallel, either a single larger 12v or 105's again in series. The latter choice would give you more 105's to move to your house bank should it again become necessary. It's OK (although not ideal) to use deepcycles for starting but not starting for deepcycle.

Thanks for that Beooksie and your comments on the Novakool. The doors are cold suggesting deficient insulation. I have an idea for that. Also, I phoned Novakool (thereby are located close to,where I keep my vessel) and the fellow indicated the best option using extra fans is to try and direct the fan to directly remove hot air, rather than just blowing air over the top of the units do there is passive flow out a vent. The units are located under the watch berth in the pilot house. There's lots of airspace down there, but sometimes the Pilothouse can be quite warm.

The voltage measurements I quoted were for the batteries in operation with normal systems (fridges etc.) and not on charge. When they are on charge the readings are in the 13.5 and slightly higher.

There is some sort of a way to set up the link monitor to provide readings on remaining hours of operation at current loads. If these are set up correctly for the battery banks, they are indications readings of anywhere from about 50 hours to over 100 hours, depending if the fridge, webasto or inverted and AC lighting is operation. Still I am still uncertain as to my interpretation of the readouts for some of the features. There is no air conditioning units on this vessel. As mentioned earlier, there is no evidence of brown outs, something I had observed on other boats I have operated on bare boat charters.

Jim

I would like to thank Celectric for the recommendation on the book by Nigel Calder. I got the Kindle edition and am going through the section on Batteries right now. The topics all start with explanations of basic concepts and develop them from there. I now know what equalization is all about.

Hmmm! I found some spelling and grammatical mistakes on my previous post made from my iPad using the Trawler forum app (recovering from anaesthetic from oral surgery today is my excuse). It seems I am unable to edit my post to correct these mistakes from either my iPad or from the computer even though the login information is the same for both devices. I edited my earlier post from the computer. Go figure.

Jim

JDCAVE said:

It seems I am unable to edit my post to correct these mistakes from either my iPad or from the computer even though the login information is the same for both devices. I edited my earlier post from the computer. Go figure.

Jim

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The forum software has an arbitrary time limit for editing your post. I believe it is 120 minutes. Whether accessed through app or web browser.

Nova cool. Hmmm i just installed one a few months ago.

They do in fact have an output for a fan drive. It used to be an option but now appears to be included which is good. Hopefully your unit has it.

I cobbled a fan drive years ago for my very old, now gone, Norcold.

The fan is located at the top of the fridge cavity and blows to the outside of the boat. It made a huge difference in the running time of the fridge in hot weather.

I'm using the same fan for my new Novacool fridge. I called Novacool and asked how much current can the fan draw. They said up to 500mA so my 4" fan was good to go at 180 -200mA. Fuse it. I used an inline fuse holder since to gain acces to the fan I must remove the fridge anyways.

Get ONE 12V 4" muffin type fan. The best arrangement is to exhaust the cavity from the top to the outside. If you can't exhaust to outside fine, but definitely from the cavity top.

I emphasize the ONE fan. I thought, years ago, two smaller 3" ones because I had a bunch of them , would be good. They caused an unholy racket and sounded like a small jet engine. So one fan only and you will be barely aware of it.

All of these small fridges are shy of good amounts of insulation however for what they are they do a good job unless you want to go really long range cruising with absolutely minimal electric power use.

Hi C Lectric. It would be difficult for me to vent the fridge and freezer fans to the outside, but I do think there would be opportunity to enlarge the bents and/or reverts the fans and vent to the wheel house cabin from under the watch berth. I would have to examine the units to determine if additional insulation could be put on the sides of the units, but there would be an opportunity to insulate to doors, behind a false panel. We often get condensation forming on the freezer door. These are separate units installed side by side. It might be a winter project.

Jim

Jim, Sent from my iPad using Trawler

Positive venting of the fridge cavity will be a big benefit no matter where the air has to be exhausted to.

Best is outside but to the boat interior will help the fridge a lot. The fridge actually won't care. I suggest the outside because in hot weather I don't want the heat in the boat.

Just be sure there is an entry point at the bottom of the cavity for air to enter so it can pick up the heat thrown off by the fridge and then the heated air be forced out by the fan at the top.

Yup, good winter project.

Something I forgot. Since you are in the Vancouver area there are several outlets for the muffin fan. The caveat is you really want one with BALL BEARINGS. There are all kinds of cheap units with sleeve bearings but they can be noisy and rough running.

I used to get Pabst or Interfan, but they are more difficult to find now. There are several electronics outlets

MRO Electronic on Boundary Rd, Van

Or

RP Electronics , Rupert st, Van

I'd suggest a call to them first unless you are nearby to ensure they have 12VDC and ball bearing 3 or 4" fans. Insist on the ball bearings.

Jim

On Bay Pelican, also a Krogen 42, we put two 4" x 10" (size is from memory) louver vents in the bulkhead between the refrigeration units and the pilot house. Also installed a 12 volt muffin fan to exhaust heat from behind the refrigerator and freezer. Again these are exhausted to the pilot house.

Marty

Marty and C Lectric: enjoying myself in Prideaux Haven Desolation Sound today. All good advice on the fridge and freezer units. The previous owner has left a spare muffin heater fan in the spare parts inventory, and those are the units currently directing air over the top of the fridge and freezer units. The setup doesn't use the full potential of the airflow from the fans. I think I might build a venting duct system with the fan units installed inside that vent the hot air from above the RF units and through a vent out to either the Pilothouse or directly outside via a cupboard space. That would be a big improvement on the airflow behind the units. I will also look for a way to insulate the doors, and if possible the sides of the units. Insulating the doors would be easy. Insulating the sides would be a more difficult proposition.

We've been away on this trip for 10 days so far. I've gone up to two days without using the Genny. In the process, ive been carefully checking the Link 2000 to see how charge states, voltages and draws are going. I topped up the water prior to leaving and again today. The water levels in most cells were fine but a couple of them appeared to be right near the top of the plates. Today, the voltage in the battery bank was down to 12 volts so I have just operated the genny for 4 hours and they have just reached a state of "accept" charge, so near fully charged. The charger was putting out at 70 amps for most of that charge. Similarly, the engine alternator is putting out at 64-80 amps

I intend to swap out the Trojan 105's with defective cells with the T105s that are the engine start batteries. I will get a new 8D for the engine battery. We will see how that goes. It would be nice if I could get another year out of the house bank.

I'm not sure when the house batteries were replaced. The maintenance the previous owner (since 2007) did not replace them. There is a record in the log of house batteries being replaced in 2003 and nothing in the log since then. If these batteries are that old, the must be getting near the end of their useful life.

Jim

Jim, Sent from my iPad using Trawler

Jim

12 volts is too low. You should begin recharging Trojan 105s at least at the 12.2 level which is a 50% discharge. The batteries will last longer if you avoid deep discharges.

Good luck.

Marty

I agree Marty, except it happened over night. I put the genny on right way. I will do an equalization when I get back and just continue to monitor the situation. At the very least, I would like to hold off until before our 2 month cruise to the central Coast of BC next year.

Jim

Jim, Sent from my iPad using Trawler

Isnt an 8D overkill for engine start?

The PO of Dauntless had two house banks of two 8Ds each, with one also starting the engine. I consolidated them into one house bank (which those stupid Subzeros need) and added a dedicated start battery.
Also added Victron BMV 600 for $145.

As C lectric explained very well above, when running my 100+ amp Alt is only putting about 25 to 35 amps / hour back to batteries. So if I get down to minus 400 amp hours, then it takes a full day of running to get back up.
Richard

Bay Pelican said:

Jim

On Bay Pelican, also a Krogen 42, we put two 4" x 10" (size is from memory) louver vents in the bulkhead between the refrigeration units and the pilot house. Also installed a 12 volt muffin fan to exhaust heat from behind the refrigerator and freezer. Again these are exhausted to the pilot house.

Marty

Click to expand...

We did similar to what Marty referenced. We also added a relay so the fans are only on when the refrigerator or freezer are on.

If you are thinking about replacing your refrigerator/freezer, when you get back, talk to Dave Lehman at Sea Freeze in Bellingham. He's done a few custom, very efficient, 12 volt systems for some Krogens.

Bay Pelican said:

You should begin recharging Trojan 105s at least at the 12.2 level which is a 50% discharge.

Click to expand...

Interesting.... as that is exactly (12.2V) where I set my low voltage alarm at on my SOC monitor.

Among about 30 other values I can check....here are the ones most interesting to me.

The "H" list covers about anything you would want to know about your battery banks and all the alarm points you can set. When an alarm goes off, you simply check the"label" on the SOC monitor, push any button to quiet the alarm and take the appropriate action.

I love this thing! (Thanks to Flywright and FF (Who's preached this SOC for years.)

Thanks for the suggestions and comments. The muffin fans are already set up so they go on only when the fridge and freezer units start up. However hey just blow the air over the top of the units, ostensibly to vent out some small vents into the kitchen space. This isn't effective at all. So I will put some ductwork into the space and reverse the fans so the air is vented into the pilot house. I talked to the manufacturer of the units (they are located close by) and this was their recommendation.

I'm going to the boat tomorrow to run an equalization cycle, as has been suggested.

Jim

Jim, Sent from my iPad using Trawler

I have loose laid wall-to-wall carpet in the salon, due to engine hatchs, and it tends to migrate toward the fridge over time. I can always tell when it begins to buckle up under the door and block the Norcold's front vent, the run time triples.

Good airflow through the unit can't be over emphasized.

LB

Seahorse...I have one of those Victron monitors for my thruster battery bank. These are evidently AGM batteries.


Jim

Jim, Sent from my iPad using Trawler

Update

So here is the update on Electrical systems 101.

1. Got Nigel Calder's book and I am considerably more knowledgeable on this subject but there is still further to go.
2. I am now further ahead with my understanding of the Link 2000 (Heart interface). I also realize its limitations WRT just using amp-hours for reference. Also that open-circuit voltage is a tricky thing to measure as the battery bank must rest for over 12 hours for the system to equalize. That's difficult when you are at anchor and using your systems. Measuring A Lead Acid Battery State of Charge Photo Gallery by Compass Marine How To at pbase.com
3. Decided to replace the T-105's as their capacity seemed to be diminished. We are going further afield this summer and I need to be certain that we have the juice to proceed.
4. I replaced the two T-105 starter battery setup (wired in series: 12 volts) with two 12 volt Group 24's, wired in parallel. These fit in the existing battery box. Would have preferred two Group 31's but these should do the trick. These are DC-DC charged with the Balmar digital duo charge.
5. All dome and reading lights replaced with LED, except for the Halogen AC Sconce lights in the Saloon. That will be a later project.
6. Understanding SOC is a journey. I like the concept of the "Smartgauge" by Balmar. I might wire one of these up because it seems that amp-hours is a function of the age of the battery. It seems it may provide a more reliable indication of the house bank's SOC than the existing Link 2000. Like everything, the devil is in the details, I guess! Smart Gauge Battery Monitoring Unit Photo Gallery by Compass Marine How To at pbase.com
7. The Novacool Fridge and Freezer: I have taken the advice of everyone and have re-directed the existing muffin heater fans to vent directly out of the watch berth. As warm air rises, the vents are located as high up as possible. I have insulated around the units with "fiberglass pink". Its easier to work with than foam. No--I didn't insulate the radiator coils or compressor!
8. The freezer door (Stainless steel panel) was cold to the touch. I removed the SS panel which revealed a corrugated plastic panel. I attached a sheet of 1" high density foam to the plastic panel. I will likely cover this with teak paneling. I will do the same with the fridge door.
9. I still have a few other tricks to do so will keep everyone posted.

Great stuff, JDC. Sounds like you're making incremental, but important, upgrades...well planned and thought through.

Starting with Calder is a big plus. I don't recall what engine you're starting with those paralleled Group 27s, but that sounds sufficient for most of our diesels. I've got twin Perkins 4.236's and feel that upgrading from a single 8D start to twin independent Group 31's will be more than enough.

Like you, we've gone through the LED upgrades and love 'em. Replacing the halogen bulbs should be simple and get the heat out of the lighting. Lots of wasted energy there. Same goes to insulating the reefer. WTG!

With an AH consumed meter, which is the one shortcoming of the Balmar Smartgauge IMO, you'd have the best of both worlds - the ability to see in real time your power consumption and an honest SOC gauge that adapts well to the decaying state of batteries over time. Ou friend Seahorse II just installed a Smartgauge on his boat in addition to his Victron and is tracking the differences in SOC. I suspect he'll find the Balmar unit accurately predicts his aging battery condition well before the Victron. Time will tell.

FW: the Link 2000 has a readout for amp-hours used, but it has trouble dealing with measurements when you are charging, it seems (another subject).

With the Link2000 you need to properly set the Peukerts exponent. As batteries age their charge state can change. There is a long article on this as it relates to the BalMar battery SOC meter. What Peukerts basically is it takes more energy returned during charging phase then just the amp hours taken out during discharge. This varies by the battery chemistry type. Then there is also the temperature of the batteries there are many variables when it comes to discharging and properly recharging batteries. I don't even pretend to know or be able to describe them all.
Good luck.
Bill