Using of inboard engine as a generator

[Gunner065]

Good morning all,

As I'm day dreaming about the R25 SC that we put an offer on and waiting for the survey to be completed, I'm looking at potential ways to improve the vessel in meaningful ways, without adding too much to the weight or diminishing the performance or already installed systems.

As such, for power generation, I've been looking at adding solar panels (in the 300W range) with the associated controllers, etc., which can become expensive depending on where you live (I'm on The West Coast of Canada) and based on the amount and level of sunshine you get, and the energy coefficient provided by these systems.

I might have found a way to leverage the inboard engine to act as propulsion and generator all in one package. Here's a company that does it (right now for sailing vessels or wealthy powerboaters):

https://oceanplanetenergy.com/high-outp ... echnology/

Any owners out there ever look at this alternative to installing a generator and add an alternator to the Yanmar engine that solely charges a bank of batteries for Hotel services?

 

[bluestreak]

My only concern is the additional hours you be adding to the main propulsion engine; shortening engine life, etc.
Which costs more the main engine being replaced or a new generator?
Lack of a generator does give added storage space.
Just a thought.

 

[Chimo]

Taking a look at the website I believe the idea here is to take the "unused" output from the existing alternator while the engine is driving the boat and store it in new Li Ion batteries for House use. The engine is not used for additional hours. The theory is good since, once the running demands of the boat and the standard battery charger are met demand on the alternator is reduced. Nothing is for free however. Adding load to the alternator will increase load on the engine and increase fuel consumption. I'm not sure how they claim to manage the fuel consumption to be most efficient since they are not managing the engine. Running the alternator under heavier load for longer will have an effect on its life but that may be minimal. Adding extra batteries of different types adds extra weight and more complexity.

I live also on the South end of Vancouver Island and find the solar panel does a great job, even if we have some cloud. The cloud is probably offset to some degree by the long summer hours of daylight. I did add a switch to combine my thruster battery with the house batteries for 50% more capacity when on the hook and I always start the engine before I use the inverter. (There's a good example of alternator load. When the inverter is switched on there is a noticeable momentary drop in rpm and then the engine management system recovers to idle speed to compensate for the added load.)

I would add a battery first if you're concerned about house capacity reserve. Better still, I would run a season to get an idea of your real life needs before doing anything. What year is the R25SC?

 

[Gunner065]

Thanks Bluestreak for the insight, appreciated.

After doing a bit more research in the topic marine power generation specific to pleasure crafts, the resounding recommendations is to replace the stock alternator with a heavier-duty alternator.

The stock alternator that is coupled with the Yanmar 4By-2 150 HP is 12v / 15A. As such based on my research and article posted below, the recommendation is to replace with a 12V/18A or higher alternator.

Content of the article:

"Before you invest in a high-output charging system, save yourself a lot of trouble and dollars by ensuring that you buy the correct system for your application. Charging systems vary by type of boat, as well as a collection of other variables including engine type, engine room space, belt type and size, battery bank size and battery chemistry. Selection criteria you should consider include the following.

Each type of marine battery—flooded starting battery, deep cycle flooded battery, gel or Absorbed Glass Mat (AGM) battery—has its own unique charging characteristic, which affects the type and size of alternator you’ll need to charge it efficiently. The Acceptance Rate of the battery—what percentage of its total amp hour capacity it can accept—is different for some battery chemistries.

A standard flooded battery, of either the starting or deep cycle type, can accept charging current equal to 25 percent of its available capacity. Gel batteries can accept 30 percent, AGM batteries can accept 40 to 50 percent, and newer technologies like lithium ion or TPPL (thin plate pure lead, such as Optima) can accept even more. They need to be charged by a large case or extra large case alternator to produce enough charging current, due to their nearly unlimited appetite for amps.

Your alternator should be capable of delivering rated output equal to the maximum acceptance rate of your house battery bank. In other words, the alternator’s rating should be equal to 25 percent (lead acid) 30 percent (gel) or 45 percent (AGM) of your total battery capacity. For flooded batteries, size your alternator toward the bottom of this range.

As we add electrical and electronic appliances to our boats, our battery banks become incapable of handling the loads created by these new stereo subwoofers, floodlights, satellite TV systems, refrigerators and other thirsty power consumers. We start shopping for bigger battery banks or consider adding a battery which requires us to take a look at our charging system.

In most cases, your alternator’s output should equal the maximum available capacity of your battery bank. In other words, if your house battery bank is made up of flooded batteries with an amp-hour capacity rating of 400Ah, the maximum acceptance rate of those batteries would be 25 percent, or 100 amps, the ideal alternator would also be rated at 100 amps.

If your house bank consists of 400Ah capacity AGM batteries, the maximum available capacity would be 45 percent of 400, or roughly 180Ah. To maximize charging efficiency, a 180-amp rated alternator would be required. Unfortunately, mounting a large-case alternator is not feasible in many vessels."

Anyone ever upgrade to a higher Amps rated alternator? Anything to report?

 

[Chimo]

I'm surprised at the Yanmar output. The Volvo D3 alternator is rated MAX 14V/180A.

 

[bluestreak]

My R-27 has the 220 HP Volvo and I believe the alt output is 185 amps.
Don't know if there is a different alt between the 200 and 220.

 

[Osprey]

The output rating for the alternator on a Yanmar 4BY-180 is 150A.

 

[Cutwater28GG]

Lithium batteries will kick the butt of an alternator unless the alternator is properly controlled. Many do this with an external regulator. A Lot of folks are now using the wakespeed ws500 http://wakespeed.com/products.htmlfor this with lithium. Balmar makes good high power rated alternators for lithium charging.

You also need battery disconnects because a lithium battery BMS system if it attempts to shut down power to the battery can spike the voltage on the alternator killing it.
Sterling makes one of the more venerable products in the space.
https://sterling-power.com/products...rotection-device?_pos=10&_sid=c5e2998a7&_ss=r


I strongly recommend you do some research on the topic of lithium as you need to approach power management differently to lead acid. It’s definitely ready for marine applications.
The two websites of seabits.com and marinehowto.com are good on the subject as are the victron energy guys.

 

[Cutwater28GG]

Also even if an alternator is rated max at xx amps. They cannot sustain this load due to heat. Lithium batteries will suck huge amounts of power pushing alternators beyond rated specs for lead acid.

 

[iggy]

To me it all depends what you want to get out of it. In other words, how to do your boating? Do you need more A.C. or D.C. current? Inverters use more energy to make the conversion.

Batteries get heavy and cost money to setup the system and replace when needed. Watching the video, the have the system in a 40 or 45 foot sail boat that has the room and can take the wight. Pulse, there doing blue water boating were we most likely are not.

Some else mentioned, just to install an extra house battery. That would help, its a start but not a cure. I feel a genset is the way to go compared to this system. You are still using fuel, once started and size dependent you are running almost everything you need. I could be wrong, but in the long run a genset could be cheaper. The setup of this system I but is high, heavy and you need the room. Their on line estimator starts a $25K and there smallest boat used is 35 feet.

 

[knotflying]

I like "keep it simple". I do not have a generator. My 110v needs are filled by my inverter when needed. If you inquire, many a generator owner has few hours on their generator. That tells you something. Since I do not have a generator, I do not miss it. I had a portable Honda and took it off the boat for lack of use. I am sure many a genset owner will disagree with me. We all have our needs and wants. As always, it is up to the individual preference.

 

[bluestreak]

knotflying,
Perhaps those boaters in hot climates needing the air conditioner which requires AC have more hours on their generators.
I like the extra storage space afforded by not having a generator on board.