New Product Requests

[joe_db]

Are you looking to boost your amperage? I've seen a DC to dc amp booster that I want to try. Hook alt to it than it to batteries. I've seen 20 40 and 60 amp versions.

A DC-DC charger cannot really do much to boost the power output from the alternator, the laws of thermodynamics come into play.
1. You can't win
2. You can't break even
3. You have to play
At best they act like a MPPT solar charge controller and get a *little more* out of an alternator by converting a lot of amps but sagging voltage into a little less amps and a little more voltage. The tiny gains would not be even close to being worth what they cost for that purpose.
I very much plan to use one of these to charge a lithium bank when I get one, but for different reasons including limiting the power going to the bank and using the correct charge profile.

[stranded-sailor]

That is exactly what I want

Are you looking to boost your amperage? I've seen a DC to dc amp booster that I want to try. Hook alt to it than it to batteries. I've seen 20 40 and 60 amp versions.

[stranded-sailor]

Keep in mind that the A4 only has, at most, 30HP to work with. Use too big an alternator and you risk turning the A4 into a 30HP genset with insufficient power left for propulsion!

I am new to this engine but to solve this problem could you put an electric clutch pully in so that when you are looking to use engine for propulsion you could disengage the alt/generator? In this I mean have a normal smaller alt running base systems and a larger gen unit on a separate drive with clutch pully for extra charging.

[ndutton]

If using your main engine for charging, the BVI charter fleet also uses engine driven refrigeration compressors. One hour run time a day, whether under way or at anchor, meets daily needs.

[joe_db]

Joe,

Let me tell you how I handled this problem.

First, my setup. I had upgraded my alternator to a 110A Amp-Tech with an external Balmar charge controller. When the batteries were low, this would initially put out 60A at 2000 RPM for a little while, then get throttled back to 40A by the Balmar as the temp came up. (This seems to be about the practical maximum for an accessory-drive alternator of ANY size due to the low RPM.) Once the (200AH gel) batteries got close to 80% this would drop WAY back, requiting an additional FOUR HOURS of engine charging to reach full charge!

While I was cruising down the ICW, this was no issue. After 8+ hours of engine time every day, I always anchored with the batteries full, and this easily carried the refrigeration through the night.

However, once we reached Florida, and anchored to wait for a weather window to cross to the Bahamas, charging became an issue.

The 200 watts of Solar charging I had just wasn't enough. I had to run the engine for 3-4 hours each evening to make sure the batteries would have enough charge to be above 50% by morning.. This was unacceptable because of both the fuel usage and the amount of heat it put into the cabin.

So I went ashore and bought a little Honda 1000ei "suitcase" generator. This thing is a marvel. It is light (19 lbs), quiet, and sips fuel. The A4 consumes ~ 1gal/hour. The Honda will run for up to 12 hours on a single tank of gas, a tank being only 0.55gal!!

I could perch it on the stern rail and use it to run my shore charger. A couple of hours was enough to get the batteries up to 80%, and this would be enough last through the night without going below 50%. An additional bonus was that it put no heat into the cabin, making things more comfortable for the crew and putting less load on the fridge/freezer, reducing it's power consumption.

BTW, we were at anchor for 10 days before a weather window opened. This system worked perfectly. And it was a blessing in the Exumas, where gasoline is scarcer than water!

This season, I upgraded to 400 watts of solar, and am in the process of upgrading to Lithium (LiFePO4) batteries. Because of Lithium's ability to stay in bulk charge up to about 95%, I'm hoping the solar will be able collect more than enough energy (on average) to meet my daily needs, and the big (560AH) Lithium battery will get me through 2 or 3 days of no sun.

And I'll still have the Honda to fall back on!

This is exactly why bigger boats have generators, or at least one reason, at some point using the main engine for charging gets to be inefficient and expensive.
Also illustrates why I need a lithium bank sooner or later

[joe_db]

That bracket only offers 9" from crankshaft to alternator - not enough to get you high and outboard enough to clear the starter. However, if you have a late style flywheel housing with the flat steel cover you have a more robust casting especially if you are willing to cobble some extra bracketry on it to secure the new cover/alternator bracket. You also have a partial pattern to start creating your own home made bracket probably from thick aluminum. There would remain the need for a sheave and crankshaft adapter ( I think Moyer sells one ). Your approach solves the parallel axes of rotation issue more easily than mine.

I have the late engine with the sheetmetal cover. I think a bigger version of that bracket will work, I need to put a pulley on the crank to get the alignment fore and aft just right before I cut metal. The bracket they are selling actually would help with that, I can bolt it up well enough for static testing at least.

[joe_db]

There's a definite rule in electrical design and practice for reliability and longevity: max. 80% loading to design capacity.

Small wonder your alternators survived only three seasons.

Yup - running it hard at low RPMs is tough duty. Now I have temperature control on it I am looking to get longer shop intervals, maybe infinity Speaking of 80%, I can turn the field down to 80%, I may do that.
My brother was impressed when the alternator died in mid-cruise once. It was off and the spare on in about 20 minutes. He said "Obviously this is not the first time this happened"

[joe_db]

Joe, seems like a lot of work both for you and the A-4 once done. Have you considered "solar"? I built my own solar for my Bene which had both a freezer and fridge for about $600 bucks. It was 350 watts and it would keep up even on cloudy days because it was also cooler and less load for cooling. It is silent and quite reliable. The biggest reason was I did not like charging with the diesel for a few hours every day at anchorage, more time to play. I often did not even plug in at the dock after a cruise as I would be heading out again the next weekend.

I bought a good Victron controller and got my panels on Craig's List from a construction over run, many available. The controller was more than the panels.

Since you have a big boat I think there should be room. I mounted mine to make shade as an aft bimini.

Dave Neptune

I love my solar cell, it cut charging time by about 2/3s when sitting at anchor in sunny weather. Say once every third day vs. daily.

[edwardc]

....
2. Charging at anchor means either annoyingly high RPM or not very many amps. I would really like a better ratio. ...

Joe,

Let me tell you how I handled this problem.

First, my setup. I had upgraded my alternator to a 110A Amp-Tech with an external Balmar charge controller. When the batteries were low, this would initially put out 60A at 2000 RPM for a little while, then get throttled back to 40A by the Balmar as the temp came up. (This seems to be about the practical maximum for an accessory-drive alternator of ANY size due to the low RPM.) Once the (200AH gel) batteries got close to 80% this would drop WAY back, requiting an additional FOUR HOURS of engine charging to reach full charge!

While I was cruising down the ICW, this was no issue. After 8+ hours of engine time every day, I always anchored with the batteries full, and this easily carried the refrigeration through the night.

However, once we reached Florida, and anchored to wait for a weather window to cross to the Bahamas, charging became an issue.

The 200 watts of Solar charging I had just wasn't enough. I had to run the engine for 3-4 hours each evening to make sure the batteries would have enough charge to be above 50% by morning.. This was unacceptable because of both the fuel usage and the amount of heat it put into the cabin.

So I went ashore and bought a little Honda 1000ei "suitcase" generator. This thing is a marvel. It is light (19 lbs), quiet, and sips fuel. The A4 consumes ~ 1gal/hour. The Honda will run for up to 12 hours on a single tank of gas, a tank being only 0.55gal!!

I could perch it on the stern rail and use it to run my shore charger. A couple of hours was enough to get the batteries up to 80%, and this would be enough last through the night without going below 50%. An additional bonus was that it put no heat into the cabin, making things more comfortable for the crew and putting less load on the fridge/freezer, reducing it's power consumption.

BTW, we were at anchor for 10 days before a weather window opened. This system worked perfectly. And it was a blessing in the Exumas, where gasoline is scarcer than water!

This season, I upgraded to 400 watts of solar, and am in the process of upgrading to Lithium (LiFePO4) batteries. Because of Lithium's ability to stay in bulk charge up to about 95%, I'm hoping the solar will be able collect more than enough energy (on average) to meet my daily needs, and the big (560AH) Lithium battery will get me through 2 or 3 days of no sun.

And I'll still have the Honda to fall back on!

[ndutton]

There's a definite rule in electrical design and practice for reliability and longevity: max. 80% loading to design capacity.

Small wonder your alternators survived only three seasons.

[Dave Neptune]

Joe, seems like a lot of work both for you and the A-4 once done. Have you considered "solar"? I built my own solar for my Bene which had both a freezer and fridge for about $600 bucks. It was 350 watts and it would keep up even on cloudy days because it was also cooler and less load for cooling. It is silent and quite reliable. The biggest reason was I did not like charging with the diesel for a few hours every day at anchorage, more time to play. I often did not even plug in at the dock after a cruise as I would be heading out again the next weekend.

I bought a good Victron controller and got my panels on Craig's List from a construction over run, many available. The controller was more than the panels.

Since you have a big boat I think there should be room. I mounted mine to make shade as an aft bimini.

Dave Neptune

[hanleyclifford]

If I do it the way you did I'll need to dig up a junk engine to work on.
I was thinking about something like this, but designed for the bolt pattern on the front of the A4.
I can mock it up in wood first and then get it cut in metal.

That bracket only offers 9" from crankshaft to alternator - not enough to get you high and outboard enough to clear the starter. However, if you have a late style flywheel housing with the flat steel cover you have a more robust casting especially if you are willing to cobble some extra bracketry on it to secure the new cover/alternator bracket. You also have a partial pattern to start creating your own home made bracket probably from thick aluminum. There would remain the need for a sheave and crankshaft adapter ( I think Moyer sells one ). Your approach solves the parallel axes of rotation issue more easily than mine.

[hanleyclifford]

If I do it the way you did I'll need to dig up a junk engine to work on.
I was thinking about something like this, but designed for the bolt pattern on the front of the A4.
I can mock it up in wood first and then get it cut in metal.

Are you thinking of sandwiching the plate between the block and the flywheel housing or fabricating to mount on the front of the flywheel housing? If the former there is the problem of moving the flywheel forward in it's housing perhaps by means of a crankshaft adapter but that means disturbing the basic engineering of the engine. If the latter you are only working with 1/4 20. Is that robust enough?

[joe_db]

If I do it the way you did I'll need to dig up a junk engine to work on.
I was thinking about something like this, but designed for the bolt pattern on the front of the A4.
I can mock it up in wood first and then get it cut in metal.

[hanleyclifford]

Several things going on:
1. Full fielding a slow turning alternator is a worst-case situation, lots of amps in the field, slow turning cooling fan. Before I had a temp sensor I was lucky to get 3 years between shop visits, now at least it backs off when too hot, which leads to....
2. Charging at anchor means either annoyingly high RPM or not very many amps. I would really like a better ratio.
3. I have a 4D thin-plate AGM that will take a LOT of amps. It would be really nice to be putting 100 amps into it instead of 50 in an hour.
4. Future plans include a big lithium battery and electric refrigeration.
5. I have the horsepower thing covered, I can switch to small engine mode which caps the field at 50%. It actually gains me about 100-150 RPM when the alternator is going full blast and drops the charging amps from say 58 down to 18-20. This is way better than just turning the voltage down, it still hits the target voltages eventually, it just takes a lot longer.
6. I like new inventions, this is a challenge.

And a challenge it will be. I don't think it can be done in the water unless you have a spare engine to use as a mock up. It is vitally important that the alternator axis of rotation be parallel to the crankshaft within very tight tolerances. It will be especially challenging using the late head. As you can see I use the early head even though I have a late engine. Looking forward to following your project.