Internal alternator regulator or external

[belizesailor]

Or something totally different....

I just had an intetesting email exchange with Sterling. Never knew they had such an extensive product line. Specifically their alternator powered battery chargers I found quite interesting. Not a regulator per se, but simply a smart charger driven by the alternator. Cool idea I think.

Eliminates the annoying tendency of external regulators to cause false alternator alarms and temporarily malfunction tachs.

A bit more expensive solution though.

Anybody running one of these?


http://www.sterling-power-usa.com/St...rycharger.aspx

[GrahamHO]

Originally Posted by belizesailor

Or something totally different....

I just had an intetesting email exchange with Sterling. Never knew they had such an extensive product line. Specifically their alternator powered battery chargers I found quite interesting. Not a regulator per se, but simply a smart charger driven by the alternator. Cool idea I think.

Eliminates the annoying tendency of external regulators to cause false alternator alarms and temporarily malfunction tachs.

A bit more expensive solution though.

Anybody running one of these?


Sterling Power 12 volt, 130 amp Alternator to Battery Charger

No I don't know these. But if it is allowing a higher charge rate than the internal regulator
alone; it must be fitted with heavy output cables to handle the extra wattage as with my Ample Power ex regulator . If it doesn't need heavier cables (manufacture info?) it can't be putting out a higher charge. The higher initial charge is a benefit of external regulators. Likewise the need for double pulleys with a higher output.

My Yanmar and I'm sure others get their tacho reading from a reed switch near the flywheel.

[OceanSeaSpray]

All the power still needs to come from the alternator, which is never going to produce more than when at "full field" at any given RPM... so much for the fantastic claims.

And why would you go to a "solution" that requires handling the full output current to achieve control, when the same can be done just by controlling the field? To avoid having to do anything to the alternator... that is a bit thin as a justification, considering reliability, complexity and cost aspects!

[sailinglegend]

Originally Posted by belizesailor

....I just had an intetesting email exchange with Sterling...... their alternator powered battery chargers I found quite interesting. Not a regulator per se, but simply a smart charger driven by the alternator. Cool idea I think....

This is just an external regulator that doesn't need the alternator modified. But because of the way it works it is very inefficient when compared to a standard external regulator that controls the field current. Yes it charges faster than an internal regulator but it turns OFF the house bank charging for 3 minutes every 20 minutes - it says to charge the starter battery but it's probably to let the alternator cool down! That's 15% inefficient. It loads the alternator to provide a low output voltage but high current and then amplifies the voltage up to about 14.8 volts. This DC to DC amplifier that can handle high currents must be about 15% inefficient. So a total of 30% lost compared to a similar external alternator regulator like a Balmar.

All this because people can't be bothered to remove an alternator and get it modified! Clever idea yes to get around a warranty issue if you modify or change the alternator, but bad engineering. There are lots of posts going back years for this old product.

[Abgreenbank]

The stirling alt to battery charger works very well, I don't think they suggest you will increase the maximum output of the alternator, just encourage it to produce more output for longer. As for cost, a lot cheaper than a new larger balmar alternator, and in my opinion very cost effective, Mr Stirling has some interesting videos on batteries and alternators, maybe too simplistic for some, but very informative for others.

It may be inefficient but my 120amp rated hitatchi alternator still pumps out over 100amps after charging the house bank after over an hour, or that's what my clamp meter on the battery cable says, maybe that's the 15% inefficiency or maybe it's my dumb hitatchi alternator producing more than it's rated output. Could be I'm just too lazy to spend £800 on a balmar alternator.

Regards

Ab


Sent from my iPad using Cruisers Sailing Forum

[Abgreenbank]

Originally Posted by sailinglegend

This is just an external regulator that doesn't need the alternator modified. But because of the way it works it is very inefficient when compared to a standard external regulator that controls the field current. Yes it charges faster than an internal regulator but it turns OFF the house bank charging for 3 minutes every 20 minutes - it says to charge the starter battery but it's probably to let the alternator cool down! That's 15% inefficient. It loads the alternator to provide a low output voltage but high current and then amplifies the voltage up to about 14.8 volts. This DC to DC amplifier that can handle high currents must be about 15% inefficient. So a total of 30% lost compared to a similar external alternator regulator like a Balmar.



All this because people can't be bothered to remove an alternator and get it modified! Clever idea yes to get around a warranty issue if you modify or change the alternator, but bad engineering. There are lots of posts going back years for this old product.

Few minor errors here, it doesn't turn OFF the house bank charging for 2.5 minutes every 15 minutes it just stops the boosting so both starting and house batteries charge.
Most Dc to Dc amplifiers have better than 85% efficiency.

So if this unit is only 70% efficient can I assume then that a 100amp rated alternator can only charge at 70amps max?

Well in the real world I used a clamp meter on the house bank cable and saw 126amps from a hitatchi 125amp alternator after around 30 minutes charging with a stirling 160amp alt to battery charger, is this possible?

Yes I'm sure that there are better engineered ways to improve alternator charging, but the stirling power alt to battery charger works for me.

Regards
Ab


Sent from my iPad using Cruisers Sailing Forum

[belizesailor]

Originally Posted by GrahamHO

...

My Yanmar and I'm sure others get their tacho reading from a reed switch near the flywheel.

Unfortunately many, like my Volvos, get their tach feed from the alternator so ext regs tend to create issues when the batts reach full charge and they shut down output. Ive considered refitting an optical or mechanical tach sender, but its just not bubbled up to the top of the todo list.

[barnakiel]

Originally Posted by belizesailor

Or something totally different....

Yep.

I had them twice - one big one (silver, I think 130 or 160 A)on a cat (Yanmar + big alt) one small (I think 80 A, red) on a 40' boat with a plain vanilla alt (about 80A).

If I relied heavily on alt as a power source, I would have one of them on my own boat too.

Very simple to set up. Good stuff.

b.

[geoffr]

Graham,

Yes Ottawa is great in the summer (and has the largest sailing community per capita in Canada). We have taken the Rideau Canal once and loved it - S/V Geru: Beautiful Rideau

We aren't confined to the Ottawa as we are on the lower Ottawa so we can get out to Montreal on Kingston. Unfortunately confined to the yard due to major overhall work as we are redoing the bottom, engine, bow thruster install etc...

Originally Posted by GrahamHO

By the way Geoffr, I see you are in Ottawa. It is a beautiful city. I was there again a couple of months ago visiting my daughter. Do you take your boat down the Rideau Canal? It must be frustrating to be confined to the Ottawa River.

[wsmurdoch]

Originally Posted by OceanSeaSpray

Yes, I got that. But you have a manual system and you need to manage the switch.

If you add a resistor like I was describing, what happens is that you tune the alternator torque curve to suit your installation and it becomes usable throughout the whole rev range without switching anything or overheating.

It is very effective, because stator heating varies with the square of the current: if you run 80% of the current at a given RPM, you only incur 64% of the heating.

When the sensor cuts it back, it tends to be more aggressive, because by then you are too hot already.

I de-rate alternators this way all the time.

I dug around in the electronics junk box in my attic and found five low ohm power resistors. I am going to give a resistor in the circuit to the alternator field winding a try. It will be easy to do. I have a male/female spade in-line connector in the field wire near the alternator. I'll just crimp a male and female connector on each lead of a resistor and stick it in at that point. By series/paralleling the resistors, I can get any resistance from about 0.1 ohm on up. I'm hoping that running a slightly crippled alternator will end up giving me a faster charge than one that alternates between 100% and 50% as the alternator alternately overheats and cools off or an alternator that runs steadily at 50% with switch in the alternator temperature sensor circuit closed and the alternator running in small engine mode.

Thanks for the idea.

[Maine Sail]

Originally Posted by wsmurdoch

I dug around in the electronics junk box in my attic and found five low ohm power resistors. I am going to give a resistor in the circuit to the alternator field winding a try. It will be easy to do. I have a male/female spade in-line connector in the field wire near the alternator. I'll just crimp a male and female connector on each lead of a resistor and stick it in at that point. By series/paralleling the resistors, I can get any resistance from about 0.1 ohm on up. I'm hoping that running a slightly crippled alternator will end up giving me a faster charge than one that alternates between 100% and 50% as the alternator alternately overheats and cools off or an alternator that runs steadily at 50% with switch in the alternator temperature sensor circuit closed and the alternator running in small engine mode.

Thanks for the idea.

If you have a Balmar regulator (Xantrex XAR is a Balmar) this feature is already built in. It will be called "Amp Manager" or "Belt Manager" depending upon the age of the regulator... A few minted with the magnetic screw driver and you've now current limited your alt.. Much easier than resistors and easy to adjust up and down to get it just right..

[OceanSeaSpray]

Originally Posted by Maine Sail

If you have a Balmar regulator (Xantrex XAR is a Balmar) this feature is already built in. It will be called "Amp Manager" or "Belt Manager" depending upon the age of the regulator... A few minted with the magnetic screw driver and you've now current limited your alt.. Much easier than resistors and easy to adjust up and down to get it just right..

Indeed. If you don't... a few minutes spent with power resistors yield the desired outcome for a few dollars only and much higher reliability.

Incidentally, you don't current limit the alternator by doing that (either way): you de-rate it. If you rev it fast enough, it will still go to full output, but with more cooling.

From memory, I have always ended up with values between 0.33 and 1.2Ohm or so. 0.5 or 1.0Ohm would be good starting points. With external regulators, the wiring going to the brushes sometimes adds some resistance already.
As you can freely disconnect/reconnect the field while the engine is running, it is very quick to try a few combinations keeping an eye on the amp meter.