| Charging system check out [message #237200] |
Thu, 23 January 2014 17:49  |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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Thanks to Ken B. for developing and Gene for posting the flow chart on the 49'er blog.
The test is to see how many different opinions can be generated from one set of data.
Using Ken's flow chart:
Engine running headlights on
Alt terminal on isolator=14.33v
Eng batt terminal = 14.31v
House batt terminal = 13.55v
Engine off lights off:
Alt terminal = 13.13v
Eng batt = 13.12v
House batt = 12.89v
I'm going through this exercise because of the voltage reading on the Alt Terminal when the engine is not running!
Seems to me it should be zero with the engine off. I assume the isolator has gone south and is keeping the Alt and Engine batt connected.
Other possibilities or problems??
Thanks for input
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: Charging system check out [message #237220 is a reply to message #237200] |
Thu, 23 January 2014 20:31  |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Well, Matt is right, your isolator is only isolating the house battery from the automotive system right now, and either the automotive side (engine side) diode is shorted or another connection from the alternator to that battery exists. On a positive note, this is still a functional system because alternator charge wires are usually connected right to the battery and the diodes in the alternator stop the reverse current. From your results it appears your hose battery is getting charged through the diodes resistance and the engine battery is getting the full charge available and the house battery is isolated from the engine system. Have thought about setting mine up like that to get the extra voltage in the engine system.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: Charging system check out [message #237227 is a reply to message #237200] |
Thu, 23 January 2014 22:17 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Gene,
I agree with your conclusions. It will run that way only it will be very slow recharging of the house side battery(s).
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Charging system check out [message #237231 is a reply to message #237230] |
Thu, 23 January 2014 22:37 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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| Mr ERFisher wrote on Thu, 23 January 2014 22:30 |
there is no voltage drop in an isolator
the sense line is there to make up the voltage drop
the voltage will be the same with or without the isolator
gene
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Do you want to correct that gene? I think I know what you wanted to say.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Charging system check out [message #237237 is a reply to message #237234] |
Thu, 23 January 2014 23:15 |
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WildBill
Messages: 232
Registered: January 2014
Karma: 1
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| Mr ERFisher wrote on Thu, 23 January 2014 21:45 |
go for it
in a standard gmc charging system ( no shorted diodes etc,)
the isolator voltage drop does not change the voltage to the battery. the
alternator output is raised to make up for any diode drop so the voltage at
the battery will be will be the same with or with out the isolator.
Me go for it? Working on the motorhome today, isolator is bypassed and the poured insulation is all cracked up. That is because of the heat caused by voltage drop and diode failure. When I wanted to run one I built them out of diodes I replaced on hyway coach alternators that we're not perfect enough to go out on the rebuilt alternator. Love diodes but for what you get regarding diode capacity for what you pay IMO it's just packaging. For $30 bucks you can charge your house battery's, you don't have to compromise your original engine wiring and charging system and you don't have to rely on the sense wire. I have seen problems resulting from the sense wire as well, mostly overcharging. I guess the best feature of a small isolator is the size of diodes are current limiting so if you have a huge house bank the diodes are only going to let through what they let through and might not overtax your alternator, but bro ably blow the diode to the house bank.
On Thu, Jan 23, 2014 at 8:37 PM, Ken Burton <n9cv@comcast.net> wrote:
>
>
> Mr ERFisher wrote on Thu, 23 January 2014 22:30
> > there is no voltage drop in an isolator
> > the sense line is there to make up the voltage drop
> > the voltage will be the same with or without the isolator
> >
> > gene
>
> Do you want to correct that gene? I think I know what you wanted to say.
>
>
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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| Re: [GMCnet] Charging system check out [message #237238 is a reply to message #237234] |
Thu, 23 January 2014 23:20 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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| Mr ERFisher wrote on Thu, 23 January 2014 22:45 |
go for it
in a standard gmc charging system ( no shorted diodes etc,)
the isolator voltage drop does not change the voltage to the battery. the
alternator output is raised to make up for any diode drop so the voltage at
the battery will be will be the same with or with out the isolator.
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-.-
-. ----. -.- -...
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Charging system check out [message #237248 is a reply to message #237244] |
Fri, 24 January 2014 06:33 |
Jim Bounds
Messages: 842
Registered: January 2004
Karma: 0
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I have done a few things to be able to know what's going on. After installing my alternator light circuit (yes, I still recommend it, do it and they work fine) I wire the dash volt meter directly to the center terminal on the isolator so I can see what is actually coming out of the alternator. If the meter does not move it means the alternator is not working. The .8 volt drop through the isolator still allows a right voltage to the batteries for charging. A charge solenoid is a current sucking mechanical device that is always pulling current when the key is on. It must be a continuous duty device to dissipate it's own generated heat and when it fails (not if) your circuit fails. An isolator is an electronic device, no moving mechanical parts. In that relays are one of the 2 highest failure components in electronics, I do not see an advantage to putting one in my circuit. Your batteries still get a good charge without points that will
fail. Both living area and engine batteries are kept seperated while being charged-- AND THERE ARE NO MOVING PARTS-- I feel that is a must. I install a mechanical marine sealed switch to tie both circuits together so you can easily charge the engine battery with the living area electrical system which includes a power converter (charger) that will charge things if the alternator or isolator fails-- just fire up your generator and it's done. This I feel is a helpful countermeasure if something does go bad with your alternator.
All this said, there are and always will be 2 camps concerning isolator and solenoids-- that's America-- but I look for backups, countermeasures if there are problems to help me continue to motivate. I do not want to build in more maintenance and look to simple, easy to maintain circuits.
Jim Bounds
----------------
On Friday, January 24, 2014 2:20 AM, Bill Dolinsky <Wildbillnick@yahoo.com> wrote:
Ken Burton wrote on Thu, 23 January 2014 22:20
> Mr ERFisher wrote on Thu, 23 January 2014 22:45
> > go for it
> >
> > in a standard gmc charging system ( no shorted diodes etc,)
> >
> > the isolator voltage drop does not change the voltage to the battery. the
> > alternator output is raised to make up for any diode drop so the voltage at
> > the battery will be will be the same with or with out the isolator.
>
>
> -.-
>
> -. ----. -.- -...
I don't have a clue what -.- -.----. -.- -... Means...- /(:$;)(@&$)(/----)--....-$-'m
--
Bill Dolinsky
Edmonton, Alberta, Canada
1977 Kingsley TZE167V102169
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| Re: Charging system check out [message #237260 is a reply to message #237200] |
Fri, 24 January 2014 09:10 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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If the isolator is bad, replace it. They are not expensive and available in higher ratings that will last a lifetime. 20 min job... Longest time is disconnecting and reconnecting the negatives at both batteries to do the job
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: Charging system check out [message #237280 is a reply to message #237260] |
Fri, 24 January 2014 11:26 |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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John, et al:
This all started when I accidently discovered (sparks when grounded) that I had power at the alternator output terminal when the engine wasn't running.
I removed the alt wire from the isolator and determined that the power was not coming from the alternator. Then tested and found voltage at the isolator alt terminal. Since the voltage was essentially the same on the engine batt and alt terminals but lower on the house batt terminal I assumed the isolator had failed.
I already bought a new one but since I, like Rob M., am electrically challenged I wanted to know if there was any other explanation for the symptoms.
Thanks to all and thanks again to Ken B. for the write up. Many of us will benefit from that.
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: Charging system check out [message #237334 is a reply to message #237200] |
Fri, 24 January 2014 19:01 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Gene have a look see at the wiring, and charge and load test the batteries. A shorted cell battery presents a lower impedance to the charging system
John Lebetski
Woodstock, IL
77 Eleganza II
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| Re: [GMCnet] Charging system check out [message #237754 is a reply to message #237226] |
Tue, 28 January 2014 07:05 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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As long as the sense witre is correctly placed, the diode dropis only a heat issue - which the heat sink takes care of nicely. You'd have to wonder, does the solenoid take more power over time than the diodes? Either way, the power used is quite small.
--johnny
From: Bill Dolinsky <Wildbillnick@yahoo.com>
To: gmclist@temp.gmcnet.org
Sent: Thursday, January 23, 2014 11:09 PM
Subject: Re: [GMCnet] Charging system check out
I agree, just gotta say I don't like isolator a for the reason of voltage drop and prefer a CH24059 solenoid.
--
Bill Dolinsky
Edmonton, Alberta, Canada
1977 Kingsley TZE167V102169
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Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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