Alternator regulator question

[EdHouston]

Hi gang

I have a Motorola alternator with I think the regulator attached to the back of the alternator, I have read that an independent regulator is the best way to go not truly sure why! anyone know enough about this stuff to give advise and or explain the difference between attached and independent regulators, my alternator has given up the ghost so will need replacing.

Ed
S/V Moonlight Mile

[Dale Tanski]

Ed,

Good question and I hope this help.  I did lots and lots of research regarding batteries, alternators and regulators in the design and installation of the electrical system aboard Maruska.  I even have an article written for Good Old Boat on the subject that I have yet to submit.

There are a few good reasons why to go to a remote alternator.  One is that the regulator that is internal to your alternator is a basic, dumb logic unit that was designed at a price point... the lowest possible.   

Today's external regulators have many features.

1) Programmable – this means you can match the required charging curve to a specific battery type.  Gels and AGM's batteries have much different charging requirements than standard flooded lead acid batteries.  They require much different threshold, float voltages and charging rate curves for optimum performance and life. A good regulator allows you to select the correct program.

2) Staged – a good regulator has the ability to stage the charging load.  For instance, during engine start, a smart regulator allows the engine to start and run for a short period of time without charging.  This improves engine oil circulation during start and saves your starter and start battery.  After a period of charging, a good regulator backs off and analyzes the battery condition then adjusts the charge rate as required with the data it acquired.  Once again this improves battery life.

3) Temperature – a smart regulator monitors alternator and battery temperature adjusting the output accordingly.  AGM batteries are like bottomless pits.  They will turn an alternator inside out and be hungry for more.  Basically you can't charge an AGM battery too fast however you can ruin your alternator in the process if you do not have a good regulator.  Heat is the enemy.  Overheat a typical battery and it is junk.  Overheat an alternator and you've let the smoke out forever. 

4) Control – some smart regulators have a manual override capability.  This allows the unloading of an alternator with the flick of a switch.  Why would you need this?  Fifty miles to go, no wind. Over the "hum" of the engine, you hear the strange sickening noise of a dying V-belt.  Your batteries are charging at a 80 amp rate because you have been on the hook all weekend.  Charge the batteries or nurse the V-belt and turn the raw water pump to make it home.  Decisions, decisions.

If you do not have anything special in batteries aboard or if you rarely run your house batteries down deep requiring lots of amps transfer, a box stock alternator will do the trick.  If you have several hundreds of dollars in cells and you exercise them on a regular basis, a smart regulator will protect your investment and keep your onboard electronic goodies happy.  If you are planning on installing a high amp output alternator in the future, you will need a smart regulator to complete the package so maybe now is the time to start the project.

Good Sailing....  Dale Tanski

[EdHouston]

OK Dale

What regulator did you decide on and why.

I think I am going to stay with wet cells for now what system would you recomend.

I have two banks of two group 27 batteries right now but I am thinking of going to a three abnk system two for house and one dedicated to engine starting.

[Dale Tanski]

Ed,

The design of anything is a series of compromises.  I always say that I am cheap, but my wife will tell you I spend way too much money.  I do however, spend it as wisely as I can in my opinion anyway.  Such is the case of a solid, reliable electrical system.  Much of what I purchased was carefully purchased off of E-Bay over an extended period of time.

The key to a good electrical system is to analyze what your needs are.  In our case we have a need for 120vac power while away from the dock.  This required an inverter.  Although inverters have come down in price, they are still expensive in my mind, but the justification process can be tempered somewhat because a good inverter is an excellent battery charger when the shore power cord goes into the shore side receptacle.  I ended up with a Xantrex unit (an E-bay purchase) that is ratted at 2000 watts ac and 100 amps when in the battery charging mode.  It has been an excellent performer with the exception of a small lightning strike down in Maryland just before we left. 

The inverter allows my wife to brew a fresh cup of coffee at anytime (a requirement) and our kids make microwave popcorn (often).  There is something about hot fresh popcorn while on an evening sail and better still watching the occupants of the other boats looking around for the source of that unmistakable smell while out on the water.  The microwave makes food/snack prep so much quicker and safer afloat and the price today of a microwave it is a nonissue.  Do you need a marine microwave? If you are going to do popcorn under the dodger in boarding seas maybe, but at sixty bucks if it dies who cares. 

Refrigeration is also a nice convenience that we feel is a must have.  Ours is a 12 volt system that I would consider our largest user of onboard power.  Because we are on the umbilical cord until we cast off, the box is always cold when we start which helps on the electrical requirements.  Every item you run has an amp rating.  Every hour you run it equals that listed amperage times one hour.  So if you had a 10 amp item, and you used it for 2 hours, you just consumed 20 amp hours.  Add all your uses up that would occur in between battery charging and you have your required capacity.

Once you have determined what your needs are then you can determine the balance of how much electricity to store and how to replace it.  Storage is simply the capacity of the batteries aboard.  If you have a large capacity bank the frequency you will need to charge them and replace the energy will be reduced.  A smaller battery bank will require a more frequent replenishment cycle.  Batteries are the most expensive link in the supply chain both in dollars per amp capacity and life cycle replacement cost.  Theoretically, the batteries are the only item after the initial purchase will have to be repurchased again and again.  Keep this in mind when selecting you systems components.

Batteries have two distinct qualifiers in terms of quality.  One is the storage capacity in amp hours and the second is the amount of discharge/charge cycles the battery can withstand before it will no longer participate.  Flashlight batteries are inexpensive; hold considerable energy but cycles only once.  A typical car battery is reasonably priced, holds lots of energy, will accept a recharge but has a low tolerance for cycling.  When I am talking cycling here I am talking fully charged to discharged and back charged again.  The typically car battery never discharges more than 10% per start, is immediately recharged to 100%, and never sits semi discharged.  Each of the those items effect a batteries life.  Under these conditions a car battery will last 5 to 7 years.  Take that very same battery and discharge it to 50% each time it is used and it won't make the first year. 

Deep cycle batteries are designed to deep dive and recharge without significantly reducing their life.  Basically they are designed with heavier plates. They are designed this way at an increased cost.  Energy put into a battery that does not go into charging the battery, results in heat.  The difference between the energy in vs. energy charged is the internal efficiency of the battery.  The higher internal efficiency of a batteries design, the less heat developed.  The dissipation of heat during the charging cycle is one of the battery designers challenges.  Heat has two detrimental effects.  If a battery were made of all one material, when it heated up or cooled down it would remain the same relative size.  Batteries are made with various materials and each expands and contracts at a different relative rate.  This causes physical stresses within the battery and if let get out of hand can allow the batteries plates move and to touch causing a short. 

Excessive heat also improves the evaporation rate of the electrolyte that facilitates the electron flow between the plates.  You have heard the term "cooked" a battery.  The elevated temperature due to recharging can damage the battery by "boiling" out the electrolyte.  The electrolyte doesn't exactly boil, but it does evaporate leaving low electrolyte levels exposing the plates.  This reduces the batteries capacity.  The reduced capacity means a shorter discharge cycle requiring additional charging and this vicious cycle eats the battery alive.  If you own conventional flooded lead acid batteries maintain your electrolyte level weekly.  The electrolyte by the way is sulfuric acid and when is evaporates or out gasses, the acid goes into your boat along with an explosive by product... hydrogen. 

Remember in the prior post, a good voltage regulator can monitor the batteries temperature?  This minimizes the out gassing of the electrolyte.  Reduced out gassing minimizes the corrosion of metallic parts in your boat, extends the life of the battery and keeps the Hindenburg possibility to a minimum.  There are battery designs that also improve all of the above.  Gels are a better battery design.  They basically add a thickener to the electrolyte to reduce the evaporation rate which increases the batteries life.  A gelled electrolyte dissipates temperature slightly slower because it is somewhat less efficient however and temperature monitoring to prevent cookout is even more critical.  Voltage control is critical during recharge as it is the only real control method to control the heat problem that the temperature sensor detected. 

AGM batteries (absorbed glass matt) are better still.  Here designers separate and sandwich the positive and negative battery plates with fiberglass cloth saturated with electrolyte.  AGM's are almost dry compared to flooded lead acid or gel batteries.  This has several advantages.  The number one rule when buying a comparable capacity lead based battery is pounds per dollar.  The pounds you are paying for that do the most work is the lead.  A flooded lead acid battery has a high concentration of electrolyte compared to an AGM and electrolyte is cheap compared to lead.  Buy the lead.  Maruska is fitted with Lifeline AGM's.

The heat of recharge is generated by the inefficiency in the ion exchange between the plus and minus plates of the battery and is accomplished via the electrolyte.  So, it is the electrolyte that gets hot.  Reduce the electrolyte or increase the efficiency of the energy exchange and reduce the heat.  AGM's have a much higher internal efficiency so they develop less heat.  Because of that, AMG's tolerate higher rates of recharge because of their improved efficiency and they tend to dissipate the heat better.  A plus / plus.  Less electrolyte means less expansion as the temperature rises.  Less expansion, less heat, less evaporation.  Less out gassing, less hydrogen and corrosion.  The best AGM's go one step farther.  They incorporate an expansion bladder bag into the sealed case of the battery.  A bladder AGM is truly a sealed battery. When the electrolyte expands or outgases it is directed to the expansion bladder and is "recycled" or condensed when the battery cools after charging. 

So... the batteries are the storage container for you precious amp hours.  The more efficient they store and release the energy the better.  But that is only half of the story.  How we get the amp hours is the rest of the equation.  You can generate electrical energy aboard today in many methods.  Solar, wind turbine, water turbine or mechanical generation (alternator) or a combination of any of the above are typical today.  You can also convert shore power to boat power via a step down transformer (battery charger). 

What ever you do you are in the conversion business.  A solar panel converts the energy of the sun into electrical energy.  A wind turbine does the same with rotational energy transmitted from the blades and the interaction of the wind.  It is a rule of physics that every time you convert energy there is a loss (conversion loss).  The loss in most cases is thermal loss.  Friction after all generates heat.  So, your wind turbine suffers a loss when the wind energy is converted to force on the surface of the blade, and the blades energy is converted to rotational energy and the rotational energy is converted into magnetic energy and so on.  Your alternator converts rotational energy generated form the burning of diesel fuel and capturing the expansion energy that makes your auxiliary diesel spin, to electrical energy.  I short, spin the shaft, generate electricity. 

An alternator makes uncontrolled raw energy.  Buy one that has the physical where withal to withstand hour after hour of vibration, corrosive sea salt, temperature expansion and contraction, meets your required output and of course spins.  They all spin, but the pricing structure for alternators revolves around the output factor.  Buy too small of an output and you need to spin it longer.  Buy too big of an output and it cost a lot of horsepower to spin it. 

There is one threshold for the average alternator that is very important, the required transmitted horsepower needed to deliver that rated output. The threshold I am referring to in our case is somewhere around 80 amps.  The horsepower to spin the alternator and deliver 80 amps is at the maximum limit of the mechanical conversion capacity of a V-belt.  All smaller marine applications I have ever seen spin the alternator via a drive belt and a set of pulleys.  V-belts are the standard because they work and they are cheap. 

Although V-Belts come in a variety of sizes and each has a horsepower rating, the size requirements of our marine applications narrow the application field to but a few.  The Westebeke/Perkins people designed and installed a one V-Belt drive system.  I believe you Universal people have the same set up.  The one belt drive provides more than enough HP transfer for the raw water pump and the stock alternator. 

The stock alternator on a 4-107 puts out roughly 35 amps.  All is well and good until we slap a 120 amp alternator on the stock single belt drive system and literally turn the belt to dust.  The rotational conversion heat load over the 80 amp mark, "smokes" the belt.  In an effort to re-write physics, people switch to serrated V-belts to attempt to improve belt traction to minimize the slip.  I have seen turnbuckle belt tensioners installed to "optimize" the contact friction between the pulley and the belt surface. Perkins even put out a service bulletin long ago warning of excessive loading of the pulley end of the crankshaft by "improved" belt tensioners.  Apparently the crankshafts break between the crankshaft bearing journals from the added bending load.  Ya can't get something for nothin folks!  I have even been asked by people why their high amp alternator won't put out the ratted amperage.  The answer of course is... somewhere over 80 amps the drive belt begins to slip.  If you want to properly power an 80 plus amp alternator you must improve the alternator drive system. 

On a 107 or 108, this is not an easy thing to do.  It is actually easy, if one belt will power 80 amps two belts in tandem will handle about 160 amps.  The problem is when 107's and 08's were designed the requirements for a 100 amp plus alternator were unheard of, so a dual belt drive system was not designed and parts are not available.  There are a few aftermarket V-belt parts out there but good luck.  There is a complete conversion kit available from. http://www.tadiesels.com/sepentine.html  If you go to a high amp alternator you must improve your drive system or you are wasting your money.

I machined my own dual V-belt system.  I like the universal availability of V-belts and the redundancy of two drive belts instead of one.  I added a little twist of course, I overdrive my alternator.  The faster you spin an alternator the more it puts out.  On a marine diesel, rpm's are relatively low.  At a reduced cruising rpm or idle, the output of an alternator is not 100%.  By modifying the pulley diameters, I increased the rotating speed of the alternator for each revolution of the engine. So at any given speed my alternator turns at approximately 20% faster than it normally would in the stock configuration.  We have plenty of horsepower, more than we need to move the boat so I stole (converted) some to spin the alternator faster.  More amps at less engine RPM's.

Batteries – check... Alternator – check... we are on to the voltage regulator.  I pretty much covered that issue with the last post.  Maruska has the Balmar ARS-5 (E-Bay), but there is more.  I also fitted her with the Balmar Duo-charge (E-Bay).  This is a slick unit.  The alternator charges the house batteries first and foremost.  Once the house batteries reach around 80% charged, the Duo-charge unit starts shifting some of the energy over to the start battery.  The battery banks remain isolated, but the Duo-charge bridges the gap so to speak.  As the house batteries reach a complete charge the Duo-charge shifts more and more energy to the start battery automatically, until both banks are completely charged.  This device maintains the maximum charging capacity out of your alternator for every turn it makes.  This is because as your batteries become full, the alternator is throttled back by the voltage regulator.  Toward the end there is a whole lot of spinning going on with little to show for it.  The Duo-charge analyses the charging requirement situation and "reloads" the alternator over to the start bank.

The last thing I will mention is monitoring.  All the batteries and charging system you have will do you little good if you don't know how much energy you have on hand to use.  They make some slick energy monitors today that are like an electrical fuel gage.  They will tell you everything like, how many hours do your batteries have left at your current rate of energy burn, or what is your average energy usage in amp hours.  With a simple glance, you can decide if you can make it through the night or should you motor for an hour or two because you need to replenish the batteries.  They will even tell you at the recharge rate you are at, how much longer until you are fully charged.  These wonderful devices are not cheap.  There is such a huge difference between 11.5 and 11.8 volts, a simple analog panel meter just won't really do the job. The width of the needle can be the difference between life and death of your precious batteries. 

Good Sailing...   Dale Tanski

[SailingSeaDragon]

Dale,

Outstanding post.

Thank you
Garner

[docpatton1]

Ed,

I don't have alot to add but I will tell you what I used on my 365 when I re-wired her in '06.

I went w/ a 120 amp externally regulated alternator and a Link 2000R monitor/external regulator. The Link 2000 is a stand alone battery monitor/and inverter/charger controller. The 2000R is the same monitor controller w/ the addition of an external regulator. The Link controls the regulator. The regulator is a 3 stage regulator that also has and "equalizer" function. The amount of amperage put out by the regulator was based on the status of the batteries as determined by the monitor.

The system has worked flawlessly until just a few weeks ago when lightening hit near my boat and damaged the external regulator portion of the system.  I DO NOT RECOMMEND this system to you as Xantrex no longer supports this product, which means they will not repair it for a fee, provide you with the schematics, or anything else.

I really liked how the system worked together and maintained the batteries. It pretty much handled eveything but adding water to the batteries. I will be looking for another system.

Hope this helps and doesn't insult,

Chris