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Topic: Dead alternator (Read 1524 times) previous topic - next topic

Re: Dead alternator

Reply #25
Thanks, all. As soon as I'm done with dishes I'll go out and hook up the engine batteries so they can start charging. As I said on the other thread about a new isolator, a new Argofet 200-2 is on the way from Alan at Bay Marine.

Re: Dead alternator

Reply #26
At this point for the test you only need to concern yourself with the start battery. This test merely checks the output of your alternator and nothing to do with batteries.
1994 U280, Build 4490
Deming, NM.

Re: Dead alternator

Reply #27
I hooked everything up again a few minutes ago. We (all of us Laborers here) are going out to eat tomorrow, Thursday, and Friday evening, so this weekend I'll crawl underneath and move the alternator cable from #2 to #4, fire up the Detroit and see what happens.

I decided to unhook the batteries for two reasons. First, I wanted to verify that I didn't have a bad battery in the mix, and second, when I cleaned the connections at the isolator I didn't want to have spitzensparksen in my face. Of course I took the opportunity today to clean up the start battery terminals.

Re: Dead alternator

Reply #28
A load test is the only way to find if a battery in a bank is bad
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Dead alternator

Reply #29
Yes, load testing is an excellent test. If wet cell, a hydrometer will also give you good insight.

But after weeks of being disconnected and still 65% of full charge, does not suggest that the batteries are bad.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Dead alternator

Reply #30
Yes, load testing is an excellent test. If wet cell, a hydrometer will also give you good insight.

But after weeks of being disconnected and still 65% of full charge, does not suggest that the batteries are bad.

I am out of my technical expertise area but I have had batteries show correct volts I think but have a weak cell.

No substitute for a hygrometer if wet cell.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Dead alternator

Reply #31
If you are going to do an adequate load test on a fully charged 8D battery you need a much bigger tester than a 100 amp one.  Peter Flemming spotted one on ebay a week or so ago and posted it.  You don't load test a bank of batteries, you load test each one individually.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Dead alternator

Reply #32
I found this one at a yard sale $25.00 many years ago. 600 amp
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Dead alternator

Reply #33
The carbon pile load testers generally are set to one half the cca (cold cranking amps) or three times the 20 hr Amp hour rating. To test our 8D AGM (O'Reilly AGM8D- 20 Amp Hour Rate (Ah): 245Ah, 1450 CCA), I set the load to about 725 amps for 15 seconds, and then read the voltage chart. To test, the battery should be fully charged, and then have sat disconnected for 8 hours or so or use the load tester on a low setting (given in the manual to suit the battery capacity) to remove the surface charge. The load tester I have is a 1000 AMP Solar (brand name), Model No. 1876. It can test batteries up to 2000 CCA. It can do 6V, 12V, or 24V batteries. I think I paid about $280 or so for it. I was looking for unit like the one Peter posted on eBay for awhile and would have jumped on that one if it had come up. It is an 800 AMP unit and would be adequate for 8D batteries. As Roger says, test each battery separately.
Don
If you are going to do an adequate load test on a fully charged 8D battery you need a much bigger tester than a 100 amp one.  Peter Flemming spotted one on ebay a week or so ago and posted it.  You don't load test a bank of batteries, you load test each one individually.
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Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Dead alternator

Reply #34
EBay new battery tester sold for $275, someone got a good deal.
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Dead alternator

Reply #35
Don has all of the details. ✔️. I found (thanks to Peter, he must live on EBay) a slightly used 800 amp tester. I won the auction for $160.  It works very well.  It is really the only way to know if your batteries are cpable of doing the job. Amazingly, two of the original Lifeline 8Ds from my coach still charge up, hold charge and pass the 15 second 750 amp load test. They run my electric chain saw out in the woods using a motor generator, a 1600 watt, 2-12v motor driven 110v generator power supply used in ambulances. They last longer than I do cutting wood.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Dead alternator

Reply #36
Geez! I leave my headlights on for a few minutes, and it's FREE.
1994 U280, Build 4490
Deming, NM.

Re: Dead alternator

Reply #37
Well, I got all the wiring moved to the new equipment in the compartment at the foot of the bed (see my other post about moving the isolator) and had the first trip yesterday. I had good charging for the first 30 minutes or so, and then it dropped to just below 12 volts according to the dash volt meter. If I turned the lights on voltage dropped to about 11 volts. Turning the lights off brought it back up.

I'm happy that it looks like I don't have a dead alternator, and the next two travel days are 200 and 250 miles, so I think that I can get by with what I have. I'll be parked for about three weeks after that last run, so I can pull the alternator and have it tested.

Re: Dead alternator

Reply #38
See reply on your other post, same symptoms.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020