Hunter 41 DS Power Consumption On The Hook

[sailtheworld79]

So we got the new boat and we've been shaking it down on shorter cruises and just found I can only run about 24 hours before my new batteries are at 12.2 volts. This is not so good. I charged them up on the hook with the generator and then isolated everything out of the system and started turning things on one by one. Turns out the fridge and freezer are drawing about 10 amps continuous and are killing the batteries in short order. Anyone else have a similar issue? I have a small Honda that I'll use on the boat but I hate listening to it. It has served me well for a long time but I try to save it for emergencies. I also found that the stock alternator is definitely inadequate even though it's rated at 80 amps. Again, I hate listening to engines on the hook. In my previous thread I had mentioned I am going to do solar but I am wondering if anyone else has done it and what sort of results you're getting. I want this boat to be completely self sufficient. No engine noise on the hook!! Any photos of a solar setup on a 41DS would be greatly appreciated. Any thoughts on how to maximize energy endurance would also be greatly appreciated!

 

[Rick486]

Based on my 44 DS experience, my batts are 3 gel 6D house. Running the fridge and freezer constantly I would top off the batts at around 5 PM, then run fridge and freezer overnight and the batts would be at 75 % in the morning. You don't say what your house bank is, although 10 amps constant draw seems high. Also, roger on the alternator. Only good for charging start batt. That alternator only puts out 13.7 volts.

 

[Ralph Johnstone]

If the alternator is still stock you will want to replace that, add external programmable regulator and upgrade the belt to a serpentine arrangement.
Great site to get advice and purchase any of your charging system needs

Marine How To - DIY for Boaters - Marine How To

For DIY boaters in an attempt to try and keep the sport as affordable & safe as possible. How To articles for sailboats and powerboats.

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Great how to articles and very responsive for advice

Fair winds and calm seas

@DayDreamer41 clearly explained the solution to the problem and gave you an excellent link back on August 02, 2021. What don't you understand ?

 

[jssailem]

rated at 80 amps

Congrats on your new boat. Smart plan to take the boat out on a series of shakedown cruises to learn and understand the systems.

The 80 amp rating is a good marketing tool but there is a hidden nasty performance issue. Your 80 amp alternator likely is only 50% efficient as it heats up it produces less to charge your batteries.

It would be wise to explore the insulation used around your refrigerator/freezer. Some were poorly installed. This causes the compressor to run more than it should, drawing down your electrical storage of energy.

 

[jeepbluetj]

1. What are your batteries? (AH capacity and chemistry. Physical size doesn't matter)
2. What is your chargers max charge current? Is it set properly for the battery size/chemistry?
3. When you charge the batteries with the genset: how long do you run it for, and what is the exact battery voltage you turn it off at? MaineSail linky
4. What does 12.2 volts mean to you? 80% discharge? 60%? is that under load or resting? And if resting, for how long? MaineSail linky Do you have a battery monitor?

With a 10A draw, I assume you have separate refrigerator and freezer, i.e. 2 compressors. 10A may be a tad high while both are running, but it's in the ballpark. But what is the duty cycle of each one? If they're running constantly the entire time, that's wrong. I'd randomly guess 33% duty, more if your insulation is poor, less if it's good. Sometimes freezers can get by with lower because they're not opened nearly as often and should have better insulation. With a 33% duty cycle, your batteries need to supply 40AH to the fridge/freezer over night (12 hrs, 8pm to 8am). Needless to say they need to provide that 40AH+ during the day too. 100AH a day for keeping the beer cold is not unheard of. Then add in all the other loads too.

I'd guess that your batteries are 4D or 8D gels or AGMs because that's all the rage for 40ish footers. Cycling AGM or gels in Partial State Of Charge (PSOC) i.e. between say 50% SOC and 80% SOC and never getting to 100% charge - the batteries will suffer a short miserable life. And your wallet will open up again to buy new batteries that are easily killed again. PSOC kills (lead-acid) batteries. Deep discharge kills (lead-acid) batteries. The sad fact is, it takes 5-6 or more hours to fully charge a battery from 50%. They've got to sit at float for a whole long time for that last 10% or so. Nobody fully charges batteries with a genset except powerboaters because no sane individual wants to listen to the dang genset that long.

Solar is a fantastic addition. I've got 400W on my bimini. I do get that 6 hours of charge each day here in sunny SoCal. And, while the sun is shining the fridge isn't pulling from the batts: the panels are feeding it. I do not have a separate freezer.

 

[Stu Jackson]

In addition to the good replies so far,

1. Have you done an energy budget?
2. How big is your house bank?
3. If you have the stock Hitachi alternator on your Yanmar engine, please note that these have been discussed hundreds of times before. Regardless of their rating, they, unlike many others, have an internal temperature compensation, made to "protect" the alternator at the expense of poor output when you most need it. Do a search on this forum under "Hitachi" and read it. If you can't find it, let me know and I'll post what I copied from Maine Sail's posts for you. Oh, what the heck, it's down below.
4. Are you sure your fridges are always working? 5A when running is not unusual, but there is usually a 50% duty cycle once the box is filled and cold, so any one fridge would use 60ah per day (5 x 24 x 50%).
5. Don't sweat the kind of batteries - yet. AGMs will work just fine if you plug in regularly.

In addition to Maine Sail's excellent website, ti which you've already been directed, you might learn from this link: Electrical Systems 101 Electrical Systems 101



Hitachi/Yanmar Alternators: (by Maine Sail)

Some alternators though, such as those made by Hitachi and found on Yanmar diesels, are dumber than a pound of beetle poop. Actually, to the alternator, they are pretty smart but to your batteries and the speed of charging they are flat out stupid. Why?

Hitachi alts with dumb regulators, and some others, limit voltage but also reduce voltage based on alternator temperature. This is a self protective feature installed in the internal dumb regulator to prevent the alternator from cooking itself. Remember voltage is the pressure that allows more current to flow. So, if we reduce the absorption voltage, then we also reduce the current the alternator is supplying.. Any battery at any state of charge simply will not accept the same current at 13.4V that it did at 14.4V and as a result the alternator will run cooler. What do you suppose this does to your batteries over time.......?

The problem is that when cold you will get 14.3V to 14.4V out of the Hitachi but as the alternator heats up the dumb regulator begins to reduce the CV/voltage limit based on the alternators internal temperature. It is not uncommon to find a Hitachi alternator at 13.4V when hot. This is REALLY, REALLY DUMB....

If you have a dumb regulator, and notice the voltage dropping, it is likely a temp compensated dumb regulator. Get rid of it or plan to buy new batteries more often.

If you have a temp compensated alternator or a Hitachi alternator on a Yanmar you really are in dire need of external regulation if deep cycling a larger battery bank.

This is from:

Musings Regarding External Voltage Regulation

and these, too:

Hitachi Alternator and Smart Regulator Instal Question - Cruisers & Sailing Forums


Most practical way to upgrade Yanmar alternator? - Cruisers & Sailing Forums

 

[Georgedoyle]

I just added 400 watts of solar and I concur with Jeepbluetj. The refrigeration on larger Hunters requires a long steady charge that you can get with solar panels during the summer in SoCal. If you have a large bimini, you won't even notice that it's there. It doesn’t really add any weight to the boat either and it’s cheaper than a new alternator set-up. Most of all, it’s quiet.

 

[Georgedoyle]

Also, it helps to have several frozen water bottles in the fridge along with your perishables and beer. This will help keep the fridge cool when the compressor is not running. Just drink the water when it melts. I always have some frozen spares in the freezer to cycle into the fridge as needed. Doesn't really cost any amps when the solar panels are keeping me in the positive during the day.

 

[sailtheworld79]

I thank all of you guys for the awesome posts here and all of the help. To be a little more clear; when we bought the boat it had no batteries. I tried to order AGM’s but was told it’d take two months to get them. As I’m in Ohio and wanted to go sail I found that unacceptable and went and bought two 4D lead acid Deka’s. I didn’t want them on the boat but to go sail I did it. Even out of lead acid batteries I expected better performance. I have a battery monitor but have yet to install it as I’m considering re doing a few things in the electrical department. After a few weeks of cruising around I’m finding two 4D’s as a house bank is woefully inadequate on this boat. As to the alternator; the Hitachi is going in the garbage post haste. It’s more or less worthless to me as has already been pointed above and in my previous post. The freezer on the boat is rated at 4.4 amps and seems to run an awful lot. I have no idea what the fridge draws. Given the design of these two units I’m unsure of how to add insulation to either of them. I’m not a fan of these dorm room type units. It’s wasted space in my eyes. Anyhow, instead of doing gels or AGM’s I’m thinking of switching over to lithium and putting as many of them as will fit here. I realize I’m going to have to change the old Xantrex inverter - charger to a newer model and get a much fancier alternator but as this boat will probably be mine for a long time to come the monetary part seems to make sense amortized over 10 years. Anyone ever change out these fridge freezer units for something better? Anyone got some photos of how they set their solar up? Thanks again!!

 

[jeepbluetj]

Uhh.. Y'all know that all AGMs ARE lead-acid batteries, right? Gels, AGMs, flooded are all lead acid. LiFePo (lithium ferrite) are not.

Thousands of cruisers world wide have used lead-acid successfully for years. Don't be thinking that lithium is a cureall. You better know your electrons when you go to lithium. Otherwise, a much more expensive battery is killed or catches on fire. No matter what the battery chemistry is you've got to balance your gosintas vs your gosoutsas. I'd much rather have CG2's over AGMs. Who abuses their batts horribly? Golf courses. What is the best $$$/performance for golf courses? GC2s. Why don't golf courses use AGMs? (cost/performance suks, that's why)

IMHO, the worst place to spend $$$ is an alternator. You don't wanna run the engine at anchor. You don't wanna run the engine for 6 hours a day to charge batts. Solar. Solar....... Solar............ If you've got a decent solar array, you don't need much alt. (You just need to be able to get past a cloudy day, and that's battery reserve)

 

[MikeHoncho]

Make sure your charger is set for LA . I question if the batteries are getting a full charge giving your are doing it on a generator and it takes hours.

 

[ice breaker]

I have the same Nova cool fridge and freezer. The fridge works great at about a 50% duty cycle, the freezer is a piece of junk. If you set the thermostat too cold, like trying to get it to 0F, it will run continuously. Many of us have added a computer fan to pull additional air past the compressor. It helps, but that unit will kill batteries in warm weather.

I have looked for alternatives to drop in but I have not found any. My compromise solution is to set the thermostat to about 25F it keeps my bag of ice frozen and keeps the frozen food sort of frozen with out running all the time. Not perfect but it helps.

 

[tfox2069]

I'll throw out another alternative here - using batteries which tolerate operating in a Partial State of Charge (PSOC). Lithiums do that as everyone knows, and so do Firefly carbon foam AGM batteries, which are more on par in terms of price with the other battery alternatives (though a bit more expensive). You'll still probably need to replace your shore charger and have an external regulator which supports Firefly charging profiles (like you would for Lithiums).

You'll still want to get some solar on the boat. Adding some flexible panels professionally sewed into your bimini is a popular and unobtrusive way to do it if you don't want to have a frame built for hard panels. Just do your research to understand the inefficiency of shaded panels, and the best way to wire your controller(s) to get the most out of your panels. On my boat my 165 flexible watt panel mostly puts enough amps into the bank to pay back my refrigeration each day I'm on the hook, so I consider that a pretty good exchange (Novakool refer only, no freezer).

 

[Stu Jackson]

I'll throw out another alternative here - using batteries which tolerate operating in a Partial State of Charge (PSOC). Lithiums do that as everyone knows, and so do Firefly carbon foam AGM batteries, which are more on par in terms of price with the other battery alternatives (though a bit more expensive). You'll still probably need to replace your shore charger and have an external regulator which supports Firefly charging profiles (like you would for Lithiums).

you've got to balance your gosintas vs your gosoutsas. I'd much rather have CG2's over AGMs. Who abuses their batts horribly? Golf courses. What is the best $$$/performance for golf courses? GC2s. Why don't golf courses use AGMs? (cost/performance suks, that's why)

Two very good answers to the same question.
Lithium is like the new kid on the block. Tons of people who really don't need them (i.e., people who are NOT truly long distance cruisers, but rather weekend warriors who sometimes go out for a week or two at a time), seem to have been the same group who jumped on AGMs and didn't understand them either.

The best bang for your buck remain wet cells, preferably GCs. Why? Well before all the "new-fangled" chemistries like AGM and lithium, true deep cycle wet cells have been used for decades. They lasted from five to seven years and they worked and they dealt with PSOC; AGMs simply do not and have other drawbacks as well, mostly needing high output charging systems to take advantage of their "advantages". Maine Sail wrote many articles about the limits of this chemistry as long ago as 2010 - not just yesterday! People understood the wet cells' 50-85-100 operational rules, did energy budgets and bothered to spend the time learning how things work. And all of this was before the internet.

And even before the new chemistry, serious cruisers realized that solar was "The" answer to maintaining a healthy electrical system.

I find it amusing that I read repeatedly now about folks obsessing about keeping their discharge below 15-20%. It's crazy. For decades, serious cruisers would run their battery storage bewteen 50 and 85% and be very, very happy with the results. Indeed, Maine Sail, in one of his excellent writeups, described the folks who he bought his current boat from cruising in just that manner, with a GASP! dumb regulator on their alternator. How did they ever survive?

Dump your AGMs, get wet cells or GCs, and solar, and be done with it. If you become a serious long term/long distance cruiser, then it's time to investigate the more esoteric chemistries. But first learn how things work with the links provided.

 

[sailtheworld79]

Two very good answers to the same question.
Lithium is like the new kid on the block. Tons of people who really don't need them (i.e., people who are NOT truly long distance cruisers, but rather weekend warriors who sometimes go out for a week or two at a time), seem to have been the same group who jumped on AGMs and didn't understand them either.

The best bang for your buck remain wet cells, preferably GCs. Why? Well before all the "new-fangled" chemistries like AGM and lithium, true deep cycle wet cells have been used for decades. They lasted from five to seven years and they worked and they dealt with PSOC; AGMs simply do not and have other drawbacks as well, mostly needing high output charging systems to take advantage of their "advantages". Maine Sail wrote many articles about the limits of this chrmistry as long ago as 2010 - not just yesterday! People understood the wet cells' 50-85-100 operational rules, did energy budgets and bothered to spend the time learning how things work. And all of this was before the internet.

And even before the new chemistry, serious cruisers realized that solar was "The" answer to maintaining a healthy electrical system.

I find it amusing that I read repeatedly now about folks obsessing about keeping their discharge below 15-20%. It's crazy. For decades, serious cruisers would run their battery storage bewteen 50 and 85% and be very, very happy with the results. Indeed, Maine Sail, in one of his excellent writeups, described the folks who he bought his current boat from cruising in just that manner, with a GASP! dumb regulator on their alternator. How did they ever survive?

Dump your AGMs, get wet cells or GCs, and solar, and be done with it. If you become a serious long term/long distance cruiser, then it's time to investigate the more esoteric chemistries. But first learn how things work with the links provided.

Well sir, I have been cruising long term for almost two decades now. I’ve always done it on smaller boats with far less complicated and energy intensive systems. My query here (if you read my previous posts concerning this new boat you’ll understand what I’m getting at) is about continuing to long distance and long term cruise on this new boat with all of its power hungry systems. IMHO, Hunter more or less designed this boat to be a dock queen. I’m trying to turn into the opposite. I don’t like running my engine, I don’t like marinas, I like to be self sufficient. My last boat was a Catalina 34 that I had setup so as to never be plugged in, ever. I never ran my generator and I never ran out of power. What I’m trying to do is figure out how to do that on a Hunter 41 DS. Fireflies, LiPo4’s, GC’s - I don’t know what’s right on a boat with huge energy draw because I’ve never owned one. Obviously I’m gonna cover it with solar panels but I’m trying to ascertain what others have done as far as placement so I don’t have shading issues. Considering this boat is going to cross oceans in the not to distant future I figured I’d go fishing for some help from others that own this boat. Sadly, I think a lot of people that own my boat don’t do a great deal of distance cruising so perhaps I’m in the wrong place?

 

[Stu Jackson]

Well sir, I have been cruising long term for almost two decades now.

That's great. Wouldn't it be interesting to exhibit that knowledge and not blame the boat? Isn't it the systems and the loads imposed? From what I've learned over my own meager 24 years owning my Catalina 34 and 15 years of C22 and C25 before that, it would appear to me that your goal is a worthy one that would require some back to basics, which I'm sure you know.

Turns out the fridge and freezer are drawing about 10 amps continuous and are killing the batteries in short order. Anyone else have a similar issue?

Just appears to me from what you wrote that you did this after you anchored out, and not before you left. Did I miss something? When I install a new battery bank, I go nowhere and spend a night or two in the marina, unplugged, to assure operation. I also break in the new bank.

Any thoughts on how to maximize energy endurance would also be greatly appreciated!

Maybe this one threw me for a loop too, given your now-stated extensive experience.

Why is solar boat-specific to you? Aren't the basics the same for all boats: size and space and shading?


I wish you all the best, safe journeys.

 

[Hello Below]

so perhaps I’m in the wrong place?

Perhaps. You have a number of individual but related questions that need addressed. So maybe you should be consulting with a marine electrician seeking the advice/information that you desire. But keep in mind they are not magicians. In the meantime let’s get down to basics.
Amps out needs Amps in. Your refrigeration, all by its lonesome, is consuming 240 Ahrs or over 3kWh per day. Gulp. Depending on the number of batteries you install, fully charge lithium will certainly extend your initial hours on the hook, but eventually you will have to recharge them by some means. I also have 2 x fridge/freezers. My daily load is between 80Ahrs and 120Ahrs. I have 335W of flexible solar panels on my bimini and dodger with two Victron 15/100 charge controllers. I recently installed 480Ahrs (4 x Trojan GC 6V) lead acid. The daily maximum the panels have produced is 1.3kWh. In my particular case between Mar and Oct of sunny days (or a minimum 4 days of cloudy days before motoring), I can go indefinitely with my current load/recharge capability.
So as a WAG you will need in the order of 700W of solar panel. That is a lot of real estate. But that takes care of the fridges only, no other loads.
This forum has fallen short in solving your dilemma. But I guarantee that someone in your area providing these services will be able to greatly assist.

Marine How To

Pacific Yacht Systems

 

[Nodak7]

On our 2006 H41DS we carry a bank of 6 6v Trojan Batteries (3 sets of 2 in series). The aH's for the bank are about 650 aH or a usable 325 aH. I have 790w of solar panel mounted in the stern. We have no genset! Our Frig and freezer are the original units and my very worst energy draw. All lights are converted to LED. Unless the Admiral wants AC (or it is very cloudy all day) there is no reason to plug the boat in or run our Honda Generator. I did consider a wind generator but decided I did not want the noise.

 

[sailtheworld79]

On our 2006 H41DS we carry a bank of 6 6v Trojan Batteries (3 sets of 2 in series). The aH's for the bank are about 650 aH or a usable 325 aH. I have 790w of solar panel mounted in the stern. We have no genset! Our Frig and freezer are the original units and my very worst energy draw. All lights are converted to LED. Unless the Admiral wants AC (or it is very cloudy all day) there is no reason to plug the boat in or run our Honda Generator. I did consider a wind generator but decided I did not want the noise.

I think this reply has been the best one I’ve gotten here thus far. Do you happen to have any photos of your solar setup you could share with me? Also, where did you put six GC’s? They couldn’t possibly have all fit under the nav desk seat.

 

[Nodak7]

I think this reply has been the best one I’ve gotten here thus far. Do you happen to have any photos of your solar setup you could share with me? Also, where did you put six GC’s? They couldn’t possibly have all fit under the nav desk seat.

The batteries are Trojan T105 Deep Cycle Golf Cart Batteries. Half the size of a 4D. Four (4) will fit under the nav station seat in the battery compartment and two (2) more will fit under the sole plate where the start battery is. Solar Panels are LG 395w (2). My Solar Controller is a Victron 150/60. I use a Xantrex Linkpro to monitor the whole system. I have attached a couple of pictures and a wiring diagram for my system!