Charging Amps going to negative

Stu Jackson · Jul 27, 2009

1. Are your batteries plugged in all week when you start this scenario?

2. If it's an isolator, then that's what's killing your voltage - they don't belong on boats and haven't for over 15 years = get rid of it and find out why you still have it after all these upgrades to your electrical system.

3. If it's a combiner, it shouldn't have anything to do with your potential issue

4. Forget about your amps for a moment, what is the Link Lite showing about your amp hours?

My guess is you still have an isolator in the circuit killing voltage, your batteries are plugged in all the time so the system doesn't need charging, and the regulator is sensing that and saying "whoops, no charge required upon engine startup."

You might also be interested in this: http://c34.org/bbs/index.php/topic,4922.0.html

Don S/V ILLusion · Jul 27, 2009

The first issue to rule out is the obvious - if the batteries are fully charged, the charge current should drop as you described until such time as the alternator/charger senses sufficient voltage drop to trigger charging. Are your batteries fully charged when you observed this?
Second, if it is in fact an isolator you have in line, the inherent voltage drop would effect the charge voltage.
Or it could be something more insidious but try the easy stuff first and regardless, replace the isolator.

sailaway78 · Jul 27, 2009

Internal regulator

If the alternator shop tested it, and the output voltage is 14.1 volts, I would guess that the internal regulator is still connected and operating. The alternator, with out any regulator should put out much more than the 14 volt number. Mine, without the internal regulator, puts out over 16 volts. It's a Hitachi, 70 amp. Not sure how this would effect the output with an external regulator also in the system, but more than likely would really screw things up. On my system, the solar panels give the regulator a voltage reading higher than the battery, and as a result they have to be turned off, for the alternator to put out fullly. I think my first thing to try would be to by pass the external regulator, and see how it effects things. Don't have any ideas about the combiner, but doesn't seem like it could cause a amp.drop.

Stu Jackson · Jul 27, 2009

garylinger said:
My concern is NOT that there is a voltage drop but that there is an apparent AMPERAGE drop. I am going to connect to shore power and turn the AC battery charger on and see what, if any, change in amperage readings result. Could there be something about the LinkLite that is giving me a false impression of the amperage?

You should be concerned about a voltage drop, because the volts and amps ARE linked.

What, again, is your "amp hours" showing?

I think what Don meant in "replace your isolator" was NOT to replace it with a new one, but get rid of it and use more modern battery connection devices, like relays or switches.

What you are describing about your battery monitor is normal. Your batteries are full when you turn on your engine. The alternator starts our putting out a bit of current (amps) and then tapers rapidly off. You turn a light on and the AMPS go to negative. Of course they do.

The shunt on the Link is reading gross amperage, in other words, what you are taking out is more than you are putting in. What's so strange?

Stu Jackson · Jul 27, 2009

garylinger said:
What I meant was that I am concerned about the negative amperage which is occurring with the engine running. The alternator should step up and increase the amperage to cover the load that I have added by turning things on.

No, no and no. You simply have the concept completely wrong.

We are agreed, I assume, that when the Link shows negative, it means that the bank is discharging, right?

Your external regulator is working properly because the amount of discharge is SO tiny that it is NOT "replenishing" what you take out and kicking your alternator up to replace the loss. That is simply not how it works.

For the first twenty three minutes of its cycle, the external regulator (which one is it?, BTW, that would help, too) it is "directing" the alternator to output at a bulk charge rate. Even so, with full batteries, the ACCEPTANCE RATE of the batteries is "pushing back" saying "We're full, we can't take anymore charge!"

As a result, there is very, very little charging going on, just the 1 or 2 amps you're seeing. The Link, as you know, shows + (i.e., input or charging going INTO the bank) as a number without a (-) sign.

The minute you turn on a load, AND the load IS GREATER THAN the 1 or 2 amps that the batteries are ACCEPTING from the alternator, the Link will show a NEGATIVE number, meaning your are drawing OUT of the banks, even though the alternator is running.

That's what I meant by GROSS amperage. 2 amps IN from the alternator running, 6 amps out from your lights and fans, Link will show (-) 4.

Neither the regulator or the alternator have any clue as to what loads you have on. All they do is charge the banks. They do NOT do it in response to loads.

Your Link is just fine.

Fix the voltage drop and rest easy.

Don S/V ILLusion · Jul 27, 2009

Gary
Replacing the isolator, which will cause a 0.7 V voltage drop, with a combiner or relay ,e.g. ACR, is a good idea regardless of what other problems may exist. More important, Stu and others can spend a lot of time helping you, all of which will be a futile effort, until you either replace it with something else more suitable or just remove it.

Stu Jackson · Jul 27, 2009

garylinger said:
I'm seriously considering removing the battery combiner/isolator or whatever it really is and just using the manual switch to control which battery bank to charge.

Don was very nice and subtle in last reply. LOSE the isolator, please. Along with an old charger, it was the FIRST thing I got rid of in my boat in 1998.

That is, IF it really is an isolator. Please learn the difference between an isolator and a combiner. If it's a combiner, it's a GOOD thing to have.

And draw yourself a wiring diagram. And learn how it does work.

As for cars and alternators and ammeters, you should buy yourself a copy of Nigel Calder's Boatowner's Manual or any other good boat electrical book that explains the difference between tapering auto regulators and boat systems.

Your car ammeter is showing positive amps because it's ALWAYS putting out amperage which far exceeds the draw. When your engine is on and the batteries are full, your smart external regulator is using it's smarts combined with BATTERY ACCEPTANCE and the alternator is putting out almost zilch, which is exceeded by your draw.

You would do well to do a search here on battery acceptance, we've discussed it many times. I wrote this because of some discussions here. http://c34.org/bbs/index.php/topic,4787.0.html

Good news: nothin's broke!

Fair winds.

Stu Jackson · Jul 27, 2009

Voltage regulator

Add to my last post.

Your Standard regulator is an automotive tapering charger made for 1964 Studebakers! Really. I looked it up on Google. OK, maybe not a Studebaker, but 1964 is so way old technology. http://www.hdtalking.com/harley_sto...d_Motor_Products_VR136_Voltage_Regulator.html

It won't do much to charge your house bank if it's really depleted, although Maine Sail and I have a difference of opinion of about that.

Use your Link to understand how the charging regimen on your boat works. The BEST way to do this is to go anchor out some night, and DEPLETE your house bank and see how it charges UP. You'll learn very little from keeping your boat plugged in all the time. The ONLY way you'll learn how it works is
by seeing how your alternator/regulator system recharges.

I take back everything I said earlier about a smart regulator, you don't have one.

That's why we ask for specifics when you explain your equipment. You have an old automobile charging system. I'll work, but it'll take longer. It will work fine for an overnight or two to put back in between the 50% and 85% of your charge, but you won't get bulk, absorption or float out of it.

Joseph Shirley · Jul 27, 2009

I just scanned your problem and the answers and want to clarify just one thing. If you have an Isolator Illuminator made by ample power, that is the same in function as a combiner, and is a good thing. If you have an old Isolator with diodes, as were used in cars with a trailer package to charge the trailer battery, then that is an old thing and should be removed/replaced.

It seems to me however that if your pos cable from the alternator goes to the isolator/combiner and then a positive goes from that connection to each battery, that you have either bypassed your isolator/combiner or you have it in parallel with your two battery banks. I don't think that either one is right.

My impression has always been that the combiner/Isolator Illuminator went between two battery banks with all the charging going to one bank which charges the other through the combiner/isolator illuminator, so I'll just bug off here.

Good luck

Joe S

Stu Jackson · Jul 27, 2009

More definitions

OK, I did get Nigel Calder's book "Boatowner's Mechanical and Electrical Manual" 3rd edition and I have been reading and studying. I have also tried to diagram my electrical system. I have read as many posts as I could regarding this subject (until the REALLY technical stuff gets too deep).

Good. It’s NOT really too technical, simply because there are only a few parts: the charging source (alternator or shorepower or solar or wind) and the batteries. All the rest is switching (and the wiring in between). Really.

I have tried to find out the difference between "isolator" and "combiner" but so far can't find any explanation - I will keep looking.

I have the second edition of Calder’s book and my book makes it pretty clear - did you use the index? Anyway: An isolator is a diode that as Don said takes a very important 0.7 V or more drop. They were originally used in the 70s and 80s to isolate batteries after charging was done without switching. They are stupid because of the voltage drop. 1 V is the difference between a full and dead battery!!!If you have one, remove it after you figure out how the system IS, and may not yet necessarily should be, wired.

A combiner is simply a voltage sensitive, battery paralleling (solenoid), a RELAY, that opens and closes under certain conditions. It closes (connects) when the charging voltage is over a preset limit, usually 13.1 to 13.4 V) and opens (stops) when the voltage goes to 12.8 V or less.

What I DO have on my boat (keep in mind that I am at least the 4th owner and previous owners did some really strange electrical modifications that I am still trying to correct) is a gray metal box that says West Marine Battery Combiner II, Model 134074 which is NOT hooked to anything. I have tried to find info about it by model name and number but can't so I don't know what it is supposed to do or how to wire it to my electrical system (the 3 connectors look way to small to attach the positive battery cables to).

I have the original 1998 WM Combiner Installation Instructions (which also used to be on their website), and the model # you quote is a 70 A two bank model, right on the manual. Email me and I’ll scan it in and send it to you. The small output wires work just fine, as you’ll see. Combiner wiring (#6) does NOT have to be as robust in size as battery (i.e., #4 to #2/0!!!) wires.

I also have an orangeish colored box with heat fins that has NO name, numbers or anything on it. That is what I assume is the "isolator" or "combiner" that is currently connected to the electrical system via the positive cables (one coming from the alternator by way of the ammeter and then 1 each going to the 2 positive battery terminals (my battery banks consist of 2 type 27 deep cycle batteries connected together for HOUSE bank and 1 type 27 starting battery for the START bank).

I am sure that the heat fins are a giveaway – it is an isolator.

PLEASE, everyone, stop using “isolator/combiner” as a phrase. It just doesn’t exist and is confusing things. It’s like saying “boat/airplane” – puleeze. For some bizarre reason West Marine is now calling the one they do sell (search on battery combiner on WM website) a "combiner/isolator," most likely using the "isolator" part of the phrase to mean when the relay opens the banks are isolated. Weird, because combiners are different animals than isolators. Must be a marketing gimmick. I can even consider the phrase "combiner/isolators," but not the two words reversed. Picky, picky picky...just an another damned engineer...

They sold the model you have, Gary, as a "Battery Combiner."

You say ” connected to the electrical system” :If I can “refine” your description: from the alternator output, to the ammeter, to the isolator to each individual bank.” That sounds somewhat strange, because you don’t mention your 1-2-B switch at all. Does the alternator output then through the ammeter to the isolator go around the 1-2-B switch?

I am trying to find out things without bothering people but when I run into dead ends, I post questions. I also have limited funds so can't really go out and buy Balmar alternators and regulators and modify my pulleys and mounts.

This is no bother, I love this stuff, but the better you can describe things, the more we can help. In the course of the past year I’ve helped many skippers with their systems, two right on this ‘board, so keep ‘em comin’, that’s what we’re here for.

Gary, you have two challenges: 1) what you have, which ONLY you can trace, ‘cuz I ain’t there next to ya; 2) what you want to do, which will determine how easy or difficult it might be.

You may want to check these:

A good description of basic "how things work": http://c34.org/bbs/index.php/topic,4949.0.html

The wiring diagram from my boat in this link, page 2, reply #23:
http://c34.org/bbs/index.php/topic,4623.15.html

I look forward to your email, I’m scanning it now for you.

Stu

Stu Jackson · Jul 27, 2009

Combiner Manual

I've scanned for you.

I can't upload it here because the file size 308 is larger than allowed for pdfs here 224. Email me.

Please note that Figure 1 is the same as Figure 9. I totally disagree with their switching options, all they wanted to do was to sell switches!

Wire the alternator output to the house bank, and follow my wiring diagram as linked above.

Stu Jackson · Jul 27, 2009

garylinger said:
You say ” connected to the electrical system” :If I can “refine” your description: from the alternator output, to the ammeter, to the isolator to each individual bank.” That sounds somewhat strange, because you don’t mention your 1-2-B switch at all. Does the alternator output then through the ammeter to the isolator go around the 1-2-B switch?

It follows the path that I stated but THEN there are separate heavy gauge (welding) cables that go from the positive terminals on the batteries back to the 1/2/Both switch, each to a separate terminal. The center terminal has another heavy gauge cable that goes to the starter solenoid. The house current comes off the the switch and goes to a bus (that is connected to a 2nd bus) that the on/off switches are attached to. I have not finished my wiring diagram to determine which terminals they come off of - that may be another area that I need to modify. It all seems like it is too round-about and just begging for voltage drops and failures.

You should have the manual now.

Wiring:

from the alternator output, to the ammeter, to the isolator to each individual bank; then from battery bank positives to the 1 & 2 posts of the 1-2-B switch, then from the C (common) post of the switch to the starter (not the solenoid) and to the DP (distribution panel.

This is good and right.

What's next?

The alternator charges the batteries. The OUTPUT of the batteries goes to the switch to determine which bank serves the loads (DP and starter). This is not roundabout, it's right.

What I'd do is rip out the isolator, and use the combiner to connect the two banks when charging`.

It's what I have, and many others, too. Check the link from my earlier post. Sounds like your PO was on the right track.

I have some ?s about the ammeter and the wiring harness. Let's keep goin'.

Joseph Shirley · Jul 27, 2009

Stu ; take a deep breath; most of us know that a combiner and an Isolator are not the same thing, and one is good and the other isn't; but Gary doesn't know what he has, so the use of the term Isolator/Combiner is to refer to his unknown unit. If you look at my post you will see that I used Isolator/Combiner when referring to his unit and Combiner/Isolator eliminator for a correct installation.

Joe S

Stu Jackson · Jul 27, 2009

Thanks, Joe. whew....

Gary has the combiner manual I sent him and we're "carrying on" offline.