Alternator Amps & waterdog's SOLAR System

[sailingdream]

I have a odd problem. I'm currently at anchor in the Thousand Islands. This is the first time I have been on a extended cruise without power. Today its raining so the solar panels are useless. So I decided to fireup the engine to juice up the batteries.
Before leaving I installed a Victron Battery Monitor and its just showing that the engine is throwing in about 10amps, which I think is pretty low. The monitor says I have used 61AH(I have 3x110AH, but they are a few yrs old so I dont really trust that they could provide over 300AH). I would think that the alternator should be throwing in way more amps into it.  The PO said he upgraded the alternator from the stock Catalina one(btw, I have a 1990) I believe it was either 90AMP or 110AMP unit.

Now much question, could have I wired up the SHUNT wrong that the engine isn't seeing that the batteries are down and need an extra load? I'm only running the engine on idle.  And even when I fireup to 2000RPM the amps going in doesn't change.

I cant say if before putting in the Batt Monitor if the ALT did provide more juice,  than it's giving me now.  

I wired up all the grounds on the LOAD side of the SHUNT and the ground for the 3x batter bank on the BATT side of the SHUNT.


Thanks, hopefully I can figure this out before I run out of fuel trying to charge up the batts or run out of batts :)

[Craig Illman]

Sailingdream - It sounds like your shunt is wired correctly. I suspect you haven't drawn your batteries down enough for the regulator to change from Acceptance mode to Bulk mode. Charging your batteries from your engine when you're still above 80% capacity is very inefficient. You also need to research what type of regulator you have and if it's setup correctly for your battery type.

If you're bored on your holiday, start reading here: http://www.amplepower.com/primer/index.html

- Craig

[Stu Jackson]

You do NOT have a problem.  That the good news.  The "other" news is you need to learn some basic battery management to enjoy your cruise.  The good news?  This'll only take a few minutes.

1.  61 ah down on a 330 ah bank.  Sounds like a night on the hook, assuming you have a fridge.  A daily use of 100 ah is not unusual.

2.  The PERCENTAGE you are down in your house bank is roughly 80%  (61/330 = 18%)

3.  The last 20% of charge is the hardest to put back into a bank.  See the discussion on ACCEPTANCE:  http://c34.org/bbs/index.php/topic,4787.0.html  You'll be interested in the original post and reply #32 on page 3 - please read the link in that post, it's very important.  Also read Reply #20 here Alternator Management: http://c34.org/bbs/index.php/topic,4454.15.html.

4.  At idle you're only running at maybe at 1,000 RPM.  The alternator most likely needs at least 1,500 RPM for any meaningful output.  But why waste engine power at the worst possible time for charging the bank?  Your 90 A alternator would not put out more than 50 or 60 A even with a 50% discharged battery at CRUISING SPEED!  You're at the battery acceptance stage where even at 2,000 RPM the batteries just won't take any more.

Run the bank between 50% and 80% to 85% and have a great cruise.  You do not have a problem.

I agree with Craig, but the regulator's another story for another day and has nothing to do with discharge or recharge related to the Victron unless the Victron's running the regulator, which would be odd.  Do the algorithm thingie on the Victron so you don't get fooled. See the GOTCHA thread: http://c34.org/bbs/index.php/topic,4922.0.html And don't waste engine energy on almost full batteries.

Oh, one other thing.  You say the alternator was only putting out 10 A. Was everything else turned off?  The shunt measures NET current, so if the alternator was putting out 25 A and you had the fridge, music and lights on (say 10 A) the Victron wold show 15 A  (25 minus 10 = 15).  Learn how the Victron works.

I'm also guessing you set the Victron on 300 ah instead of the 330.  Amp HOURS do not go away because you think the batteries are old or won't hold a charge.  Go back and reset the Victron to 330 ah, and run the engine only when the Victron says you're down 165 ah (half) - that's only for when there's no sun, hope it comes out for ya   so this isn't an issue related to the solar.  Speaking of which, what input amps are you getting with the solar on a  cloudy day?  How big a panel?  The Victron should be telling you that info (with all loads turned off).

[sailingdream]

Thanks Craig and Stu, have taken a load off my mind. I wanted to make sure I didn't screw anything up  when I installed the monitor. Since my batts has always been topped off I never saw any major AMPs going into the bank via the engine.

I will have a look at those links.

I have been averaging about 40AH overnight from sun-down to sun-up. With the refer going and the anchor light as well. Mostly LED lights in the cabin.

To answer the question about the solar panels. I have 2x75Watt panels mounting above the helm(flat). I have yet to see more than 5amps come out of them. Yesterday it was SUNNY and they helped put in about 10AH back into the bank. It was at about 43AH at the start of the morning and took it down to about 32AH before I jumped over to a fellow boaters boat for drinks.

Currently I'm down to about 85%. I will keep an eye on it and see what happens when I drop down to say 70% and give a start to the engine and see what juice the ALT puts in. I just wasn't sure if the ALT would put in some major amps to bring them back up to 100%.

I tried to do the "algorithm thingie" on the victron but was getting a bunch of weird numbers so I left at the default 1.25.(range 1-1.5)

Did noticed that when I started the engine up with no loads on the banks it was putting out 17amps and than dropped down to 10amps shortly after the startup.

Will let you guys know how things are going...

[Stu Jackson]

1.  I have been averaging about 40AH overnight from sun-down to sun-up. With the refer going and the anchor light as well. Mostly LED lights in the cabin.

2.  To answer the question about the solar panels. I have 2x75Watt panels mounting above the helm(flat). I have yet to see more than 5amps come out of them. Yesterday it was SUNNY and they helped put in about 10AH back into the bank. It was at about 43AH at the start of the morning and took it down to about 32AH before I jumped over to a fellow boaters boat for drinks.

3.  Currently I'm down to about 85%. I will keep an eye on it and see what happens when I drop down to say 70% and give a start to the engine and see what juice the ALT puts in. I just wasn't sure if the ALT would put in some major amps to bring them back up to 100%.

4.  I tried to do the "algorithm thingie" on the victron but was getting a bunch of weird numbers so I left at the default 1.25.(range 1-1.5)

5.  Did noticed that when I started the engine up with no loads on the banks it was putting out 17amps and than dropped down to 10amps shortly after the startup.

1.  You're missing the point, it's not only half a day, it's the FULL day.

2.  2X75 should get you more than that unless cells are covered by shade, or unless the batteries are close to full, which appears to be the case.  What solar regulator do you have?

3.  Ain't gonna happen.  There isn't an alternator made that, without running literally for days, will completely fill your batteries.  That's why cruisers run between the 50% and 85% area of battery charges.  It's also why solar is so good, because with the proper size and proper controller, it make up the difference.  Just ask Steve Dolling.  What alternator regulator do you have?  You still have to drive the batteries down to around 50% before you'll see meaningful input from the alternator.  70% is just the "beginning" of that area.  What do you mean by "major amps?"  You'll only see about 50% of the rated alternator output even on a completely empty (i.e. 50% discharged) bank.  100 A alternator, good regulator = 50 A input at the start of the engine.  This is because of battery acceptance, see above, NOT because your alternator has anything wrong with it.

4.  "Default of 1.25" is the Peukert equation and has nothing whatsoever to do with the Gotcha algorithm discussion.  Please read it again.  Don't change the Peukert equation #.

5.  If you don't have an external smart regulator that'll happen because if its an internal regulator it is a "tapering" charger which is not very helpful, since the amperage drops off RAPIDLY immediately after charging begins.  Again, what regulator do you have on the alternator.  An internal regulator si good for keeping your bank between that 50 and 85% but pretty worthless for the last 15% because of, you guessed it, battery acceptance.  Even a three stage smart regulator will NOT top off batteries that last 15% - alternators are just made to do that.  That's why there's solar and shorepower.

More information FROM you helps US to help you even more.

So far so good, you're in a lot better position than you thought you were.  

Hmm, for summer reading, did you by any chance bring along Nigel Calder's "Boatowner's Manual for Mechanical and Electrical Systems?"

[Ron Hill]

Sailing : Your usage of 40 amp hrs from sunset to sunup, is about what I use during the same period.
 
I'd be concerned with only 10 amps charging after a 40 AH drain.  You didn't mention what kind of voltage regulator you're using. 
It almost sounds like you have a stock internal VR which won't ever go much above 13/14 amps.  The key to charging is the VR, not the alternator per say.

During the same period on my boat I'd see 40 to 45 amps on startup then dwindling down to about 20 amps for awhile. I have a Balmar III smart VR.

Find out what kind of Voltage Regulator you have and get back with us.  A thought

[Kyle Ewing]

I recently experienced similar symptoms.  After running the battery bank (4 T105s, 6+ years old) down to about 60% charge, the most I saw from my alternator (Blue Circle 100 amp with Balmar ARS-4 regulator) was 26 amps and it tapered off quickly.  With other systems running to consume power it may have been putting out 36 amps.  My Link 10 reported an acceptance phase output of 10-15 amps (estimated at 20-25 amps with other systems running) and it stayed there for 1+ hours.

I checked the programming and changed it from factory default to flooded deep cycle.  I may also change the minimum time for the bulk phase from 36 minutes to 1 hour. 

When at shore I watched battery charger output (Truecharge 40) and noticed the output curve was similar. 

[Stu Jackson]

Kyle, because the shunt is reading net amperage, I would begin to start to think of "using" the "larger numbers" in your example, i.e., 36 and 20-25 'with other systems running'.  When ya think about it, 36 A out of our Blue Circle 100 A alternators is not that bad, in fact only a few amps off the 50 A max output I see when I start up and run "against" a 50% depleted house bank.

As I noted in the Small Engine Mode topic (http://c34.org/bbs/index.php/topic,4669.0.html) running the alternator "full out" at engine startup when you are later going to plug in is unnecessary.  If you're still cruising out there, then give your belt a rest for the first half hour or so until the alternator output, not the net amperage going into the bank, drops down to about under 20 before kicking in full output.

Heck, if you don't manually with the small engine mode, your regulator will do it for you if you have an alternator temperature sensor.  Which is what the small engine mode switch is anyway.

[Ron Hill]

Sailing : I've reread you original post and wonder as you do if you have the wires in the correct place.
Call Victron and talk to them with your question.

I've never professed to be an electrician, but a great plumber. 
It seems to me that ALL negatives MUST be wired to the "input side" of the negative shunt to have the battery monitor & collect ALL amp date, then compile it.  As I recall (wired mine back in 1994?) the "output side" of the shunt is a single #4 wire going to the main engine ground.

It's also hard for me to believe that you you have a usage factor of 10/15amps when underway.  4 amps (cycles on/off) for the fridge, radio/chartplotter/instruments about 2 amps.  Unless you also have radar and sonar etc. ON I don't believe you can get up to 10amps. 

Still waiting for your type voltage regulator.  A thought

[Stu Jackson]

The "output side" of the shunt is the negative to the engine ground.  These days they use the negative to "catch" all the amps.

[Ron Hill]

Sorry Guys, I made an Oops as Stu pointed out -- which I've corrected.  The "output" side of the negative shunt goes to the main engine ground.

Just remembered, I also did something else back in 1994.  As I wrote up in the Mainsheet tech notes I ran a #8 negative wire from that "output side" of the shunt directly to the negative buss bar on the top of the main electrical panel (Nav Station).  Also on my duel output alternator (beside the two + wires going directly to each of the 2 banks) I also ran a #4 negative wire directly from the alternator to the farthest negative battery post.

As you can see, I believe in the old addage "you can't have too many grounds!!"  A thought

[sailingdream]

Thanks guys for all the messages. I just got back to home port yesterday. So trying to get everything back in order, looks like a bomb went off down below with the rough 'seas' if you want to call it that on Lake Ontario :) . I will have a better look at the alternator and give you the details on that.

While at one of the marinas I was talking with someone and they made a comment that they had an issue with their solar control giving low amps into the battery bank so I'm thinking I have an issue with mine. Never saw more than 5 amps from the 150watt panels even when the batteries were down 100ah and full sun.

back to you shortly.....

[Stu Jackson]

Welcome home, hope you had a great cruise.

We know, literally daily, about "battening down the hatches" every time we go out.

I received this email in mid-June from Steve Dolling, aka waterdog, who is now in Neah Bay ready to turn the corner at Cape Flattery.

You can find his blog here:  http://sailblogs.com/member/blackdragon/

Anyway, regarding solar:

Stu:

You told me a while back that solar was the way to go.   I am so blown away by the new panels.  

I used a BlueSky 3024i charge controller.   I kept reading the manual over and over.   The instructions were basically hook any number of panels wired in series, parallel or anything you like and the charge controller will figure it out.   Hook up your battery bank and it will figure out if it is 12 or 24V.   That's it.  (OK you have to put in a breaker).  Diddling with dip switches to change factory defaults was optional.    I couldn't believe it.   I wired the panels in series and measured 63 Volts exactly to spec.   I hooked it up to my charging bus and boom I was getting 20 to 30A back into the battery.   The little blinky light told me when it shifted to acceptance and float. (I skipped the expensive interface module because mostly it just replicates the link functions).  All afternoon I kept turning on loads and watching my battery monitor.    The unit just responds and an amp or two goes in or out of the battery even with big loads.  It's like always being plugged into shore power without the noisy TruCharge 40 fan.  

I'm not even sure I want to bring a shore power cord!    I am free man.  No gas.  No Honda.  No burned up alternator belts.  Thank you!

I was up in Gibsons and my sister and dad came over for dinner.   She was aware that I had been installing solar panels all day.   After dinner she stands up in the cockpit looking forward on the deck and says "So where are these solar panels you installed?"   You don't even know they are there when you are in the cockpit.

search [dollingsolar]

[Kyle Ewing]

I solved my problem of apparent low alternator output.  I replaced batteries (I went with 4 Sam's Club golf-cart batteries) and now see 60+ amps of output from my Blue Circle during bulk charging when discharged to 50%.  After an hour of running the engine it's still putting out 30+ amps.  My Truecharge 40 also puts out nearly 40 amps much longer than it did with the old batteries. 

I guess another sign of aging batteries is a lower acceptance rate.