Sterling Charging Voodoo

So, as some of you may have noticed, I've been on a quest for an efficient means of charging batteries. We regularly anchor for days, and sometimes only go for an hour before another bay entices us in for a couple more days.

The last thread started was about small diesel battery chargers, but I recently discovered the Sterling 12 volt to 130 amp alternator to battery charger, which claims significantly shorter times (up to 5x faster) to charge batteries with the main engine. Maybe, just maybe, this is what I've been looking for..?

Anybody familiar with it?

Sterling 12 volt 130 amp alternator to battery charger;

http://sterling-power-usa.com/12volt130ampalternatortobatterycharger.aspx

PDF instructions;

http://www.sterling-power-usa.com/l...stallation Instructions for model AB12130.pdf

Sail Magazine review;

Hard Charging: A New Way to Charge Batteries | Sail Magazine

The separate diesel let's you put hours on an engine that is more properly loaded...the use of the main to charge batteries with one or several heavy duty (high amp) alternators with really good regulators is pretty much the same without buying a separate engine.

Using the regulators to demand the highest load possible for the longest time necessary is better for either setup anyway. People that use the main with regular or poorly regulated alternators are using a lot of engine hours and probably still undercharging their batts.

>People that use the main with regular or poorly regulated alternators are using a lot of engine hours and probably still undercharging their batts.<

With a SOC meter this can be monitored .

Not ruining only one set of small batts will pay for an SOC meter.

So it is always FIRST CHOICE of purchase items for a anchor out cruiser.

psneeld said:

The separate diesel let's you put hours on an engine that is more properly loaded...the use of the main to charge batteries with one or several heavy duty (high amp) alternators with really good regulators is pretty much the same without buying a separate engine.

Click to expand...

This is where the balancing act between cost, space, fuel capacity, and length of time on the hook between fuel stops comes into play. It's a few years until I retire, but we want the ability to stay anchored in isolated north coast BC anchorages for weeks, or even a months or more.

We're tight on space, but the PO had an extra fuel tank installed which increased fuel from 100 to 140 gallons; that's why this Sterling charging device seems so enticing.

It appears to my "innocently unawares & overgeneralizing perspective" that those extra 40 gallons would increase our time on the hook by up to 20 days, using the main engine, depending on alternator and battery bank size.

psneeld said:

Using the regulators to demand the highest load possible for the longest time necessary is better for either setup anyway. People that use the main with regular or poorly regulated alternators are using a lot of engine hours and probably still undercharging their batts.

Click to expand...

That's where we're at right now. The previous owner was a fisherman who probably did a lot of trolling, so undercharging was probably never a problem.

FF said:

Not ruining only one set of small batts will pay for an SOC meter.

So it is always FIRST CHOICE of purchase items for a anchor out cruiser.

Click to expand...

Lesson learned, and wholeheartedly in agreement!

We have the luxury of time, as the shorepower bill is paid up until March. Hope to have new system installed and ready to go by then.

From all of us new to this complex world, thanks for those of you who take the time to share what you've learned

Murray, seems like an interesting device which does about the same thing as an advanced regulator w/ temp control and an ACR. It could also be easier to install in some cases but you need to change your heavy cables not just your field wiring as with a regulatorn.
I question if it, or anything, is going to make a 100A alternator work like a 200A alternator.
I have found it easier to install 2 alternators on my boats, leaving the original for the start batteries and a good size truck alternator w/ an advanced regulator for the house batteries. You can buy a lot of truck alternators, brackets, belts, and sheaves for what a Balmar alternator costs.
One thing you can't do reliably is put much more than 100A alternator on a single belt for any length of time.

Brooksie said:

Murray, seems like an interesting device which does about the same thing as an advanced regulator w/ temp control and an ACR. It could also be easier to install in some cases but you need to change your heavy cables not just your field wiring as with a regulatorn.
I question if it, or anything, is going to make a 100A alternator work like a 200A alternator.
I have found it easier to install 2 alternators on my boats, leaving the original for the start batteries and a good size truck alternator w/ an advanced regulator for the house batteries. You can buy a lot of truck alternators, brackets, belts, and sheaves for what a Balmar alternator costs.
One thing you can't do reliably is put much more than 100A alternator on a single belt for any length of time.

Click to expand...

All great and valid points. There is a lot to be said for simplicity and time tested solutions, but it's interesting to see who's pushing things further. A serpentine belt kit is on the short list, as is a second alternator.

Choices, choices, choices...

Hello Murray, look at this site - don't be put off by the name. I am contemplating 5-100 watt panels. Don't forget the controller.
sun solar panels

Xsbank said:

Hello Murray, look at this site - don't be put off by the name. I am contemplating 5-100 watt panels. Don't forget the controller.
sun solar panels

Click to expand...

All right, now we're talking! All possibilities welcome at the table for discussion!! Solar's trickle value is being considered as well, but after the big ticket charging needs are met.

You can understand why solar is off my radar considering our 16 hour nights at this time of year

Murray:

It isn't voodoo. That Sterling device is to alternators what MPPT controllers are to solar panels, only reversed.

It presents a sufficiently low impedance to the alternator so it is "fooled" into producing more current than it would if it were charging 80% full batteries. That alternator voltage is electronically increased (just like an MPPT controller decreases solar panel voltage) to be able to push those amps into the higher impedance battery.

It might work ok for casual usage, but it is still dependent on your existing automotive style alternator. Asking such an alternator that was never designed for it to put out lots of amps continuously will result in premature failure. To put out lots of amps continuously you need heavier windings, heavier diodes and better cooling.

A large case alternator with an external 3 step regulator feeding a large house bank may be your best bet. With that you can probably add 150-200 amphours to a half depleted 800 amp hour bank in the hour or so it takes you to get to a new anchorage. How long that 200 AH lasts, depends on your usage.

David

Don't know anything about that device but I am installing two Sterling advanced regulators and two new 120/150 amp alternators this winter.
Advanced Alternator Regulator

The alternators were set up for external regulation. The alternator will feed a Promainer Alternator combiner and therefore I will be abled to charge the house bank with both alternators after the start batteries are charged.

here is some data for this discussion previously posted:




There is no question that bigger is better when talking alternators and DC charging systems. The heat issue ends up being the biggest enemy of the solid state parts as well as bearings etc on the alternator.

Using a large frame unit, then de-rating it via a smart regulator will ensure a long life for your system. Always use temp sensors on both the alternator and battery bank.

My boat came with a stock 60A small frame and when I asked it to try and charge a house bank around 500Amps, it simply could not do the job.

I then upgraded to a small frame on steroids 120A unit coupled with a smart regulator, which did an adequate job, but got REALLY hot.

Since my motor has a serpentine belt, it was a fairly simple matter to fit a large frame 200A unit, which charges my now very large 1350AH bank quite nicely. I have de-rated the alternator to 160A so it never runs at the max design in any circumstance.


If you have room and pulley/belt ability, just get a truck alternator - Ebay has lots of choices Leece/Nev 160-200A units are around $200.


It is always easier on the entire system to use less charging than you have available.

If you decide to upgrade the capacity of your Alternator, it will mean a number of 'other' costs as well.

First you must determine if your pulley/belt arrangement will be adequate. The normal rule of thumb is a single belt will safely give 100A or less. Dual belts or serpentine for greater than 100A. Determine if the side loading of the main bearing or waterpump you take off will be a problem.

As mentioned, if you change frame size, there can be mounting brackets etc to install/design.

Next, if you trade out a stock 60-70A internally regulated unit for a high-amp one, the cables will need to carry the extra juice - this normally means wire that is big enough - be sure to check a table or two for sizing properly - Don't forget fusing.

Of course, the Regulator will need to be a multi-stage unit. Balmar, Ample etc make some good equipment which will survive the marine environment well. The nice thing about these regulators is they are fully programable for the different stages of charging, battery types etc.

Then will come the 'how do I keep my start battery charged?" issue. These days an echo charge unit is hands down the best solution to the problem - Balmar, xantrex etc make good ones. This gets rid of the battery isolator - which never works well and makes more unwanted heat.

By this time you have spent some $$ and time designing a good DC system, so you will have already determined your usage needs and sized the house bank appropriately, and may decide it is time to make the bank bigger - thus necessitating buying an entire new house bank of AGM batteries to accept all these amps you now can produce.

You must also have a way of monitoring the beast - a link or other 'smart' monitor is pretty important to the health of your system.

It is a slippery slope when you really look at what is necessary to 'oversize' things.

The good news is you may just not need a generator after you get your DC system in shape.

below is a schematic showing the arrangement on my boat.

I have the ability to stay anchored in one location for up to 6 days and still be above 50% of Bank capacity. We usually stay 3 days max in any one place, but the option is there.

Good luck
Attached Thumbnails

Many thanks for the responses above, particularly the schematic. Much to ruminate on!

Murray,
I've been tossing around ideas similar to you.

The Sterling systems sound like a great improvement to standard charging systems. I like their monitoring systems as well. A lot of progress has been made in this area over the last ten years; much of which is above my head.
I share the concerns of others regarding making my present alternator work harder. I'm sure it would work well for a while, but its a bit like putting a turbo on a standard engine. Improvement in horsepower, but expect a shorter lifespan, and higher maintenance.

Another concern with us small engined guys (I have 36 hp to play with) is the installation of a bigger second alternator adds to the parasitic load of the engine, leaving less power to turn the prop. This may be good if I was over-powered, but I see it as another small negative in my case. I think you have a few extra hp to play with, so a second bigger alternator would make more sense. It would also give you some redundancy.

As I am situated in a very sunny climate, I am leaning towards going with more solar panels. I can understand this may not work well with you, especially if you use your boat much outside the summer months. Lots of ways to do it, but the most suitable varies with individual circumstance.

The Sterling device that sparked this thread has temperature sensors for two battery banks, as well as for the alternator to prevent overheating. They also make alternators which seem to meet your requirements;

Our alternators are built to provide optimum charging capacity at low rpm’s to increase efficiency, shorten charging cycles, and increase the life of your battery.

We manufacture superior products with heavy duty diodes, robust stator winding, and extra-large bearings on large alternators to ensure outstanding performance under load. Our alternators offer superior bidirectional fan cooling.

Click to expand...

Sterling Power USA - Replacement Alternator

Check out the low rpm / amp curves;

http://www.sterling-power-usa.com/library/sterling power alternators.pdf

This Internet thingy really increases ones options...remember when choices were limited to what could be bought locally, or from a dog eared catalogue?

MurrayM said:

This Internet thingy really increases ones options...remember when choices were limited to what could be bought locally, or from a dog eared catalogue?

Click to expand...

Got to admit that I agree with you on that, years ago it was "you got what you were given" particularly when you live as far away as I do....

>Another concern with us small engined guys (I have 36 hp to play with) is the installation of a bigger second alternator adds to the parasitic load of the engine, leaving less power to turn the prop.<

Not really that much of a big deal. With a 30 ft MS you are probably burning 1/2 to 3/4 GPH about 9-13HP underway.

Remember any alt load is temporary so there is no long term speed loss.

Our 33ft MS has an ancient Volvo MD 3B .2 alts and mechanical eutetic refrigeration

When the mechanical refrigeration is turned on there is a 300RPM drop , which is easily made up with more throttle. I have checked and the 2300 RPM we prop for is still observed , so back at 1650 to 1800 there is zero chance of an overload.

As the freezer stops absorbing HP ( Starts at needing about 10hp) the rpm slowly climbs and we pull back when we notice the stern wave getting too large.

Overloading a 36HP engine with a 30 ft boat could only be done with very high cruise speeds being attempted , while also charging.

Always run to the max throttle , note the RPM and pull back 300RPM and you wont be near overloading.

Murray

What is the wind like up in BC and Alaska. Bay Pelican has the good fortune to have the trade winds at a regular 15kts. Our very small and quiet wind generator produces 100ah + per day on a regular basis. I have seen trawlers (and many sailboats) in the eastern Caribbean with two wind generators and frequently the larger units.

Marty

Murray

Having spent a day or two in your neck of the woods and greatly appreciating redundancy, why not a gas genset? A small Honda is dirt cheap and will charge your batteries as quickly as the charger and battery design will allow.

Redoing pulleys and belts is not as simple as some make it sound. And you remain limited to the batteries overall capacity. Not a comforting thought when waiting out a 3 day gale. A 90 amp on engine and the Honda will provide for an easy many weeks of cruise time.

This approach doesn't limit your options for eventually putting in a small diesel if you so choose.

Bay Pelican said:

Murray

What is the wind like up in BC and Alaska. Bay Pelican has the good fortune to have the trade winds at a regular 15kts. Our very small and quiet wind generator produces 100ah + per day on a regular basis. I have seen trawlers (and many sailboats) in the eastern Caribbean with two wind generators and frequently the larger units.

Marty

Click to expand...

Winds are not consistent at all, and haven't noticed any power/trawler type vessels here with wind generators. I've taken a peek at them, but may look further. Thanks.

sunchaser said:

Murray

Having spent a day or two in your neck of the woods and greatly appreciating redundancy, why not a gas genset? A small Honda is dirt cheap and will charge your batteries as quickly as the charger and battery design will allow

Click to expand...

Wanted to stay away from gasoline but that is a good, short term option (if a diesel generator/charger is in my future) for sure as it could have other uses around the house.

sunchaser said:

Redoing pulleys and belts is not as simple as some make it sound. And you remain limited to the batteries overall capacity. Not a comforting thought when waiting out a 3 day gale. A 90 amp on engine and the Honda will provide for an easy many weeks of cruise time.

This approach doesn't limit your options for eventually putting in a small diesel if you so choose.

Click to expand...

AltMount makes what seems a pretty straight forward pulley conversion kit for Yanmars; products

Have an 80 amp alternator on engine right now, but will upgrade when new system gets installed. Sure would be nice to figure this all out by March, but there's wisdom in what you say to have a little Honda waiting in the wings, just in case.