Battery Charging Problem

[Stuart F.]

On my latest Sunday Morning ride with my 63 L-76 (after a 2 month layup), I noticed a hic-up in the cranking during my last re-start to drive it into the garage. I put my Battery Minder on the battery and within a few short hours the battery was completely dead (down to 5.5 volts). The battery is a "Restoration Battery" (AGM) and is about 4 to 5 years old (looking for paper work as my son bought it for me).

My first attempt to recharge it with my new charger got a "bat bad" shut down. Then I completely isolated the battery from the cables and the charger pulled it up to 13.9 volts in 2 hours. I re-connected the Battery Minder (and cables) thinking it would then trickle it back up to full charge. But again, within a few hours, the battery was completely dead. As it took a charge once already, I let it charge for another 2 hours and it reached 14.2 volts. So, this time I left it disconnected from the cables (and trickle charger) and let it sit overnight. The next day it checked in at a full 12 volts with my multimeter. I again let it sit for another night and it again checked in as fully charged.

As a caveat to this problem; several months ago I had trouble with the connector on the alternator that has the 2 small wires with faston female connectors within a plastic plug. The plug had rotted away after only 50 years and one of the wires was not making contact. I noticed this condition on my dash ammeter while driving. I did a temporary fix with tape, then found a replacement "pig tail" at my NAPA store. However, as my wires and fastons looked good I just used the new plastic plug with my wires (not wanting to do a splice). The plastic plug fit very tight in the alternator, and when I would wiggle it around I would hear a contact in my voltage regulator make and break. So, I cut down the plug so that it would fit more fully in. I did this during my charging efforts, but it made no difference,

Also, I have not had any signs of any starter trouble to date. Both my cables are fairly new, and my alternator was restored with new diodes installed about 5,000 miles ago. My voltage regulator was also replaced then.

I spoke with Tom at Restoration Battery last week and he had me do some additional tests and, at that time, we concluded the battery was gone. But, now I no longer believe that. He confirmed that my Battery Minder was a rather old model and not the preferred unit to use with this battery, but he didn't consider that it would be harmful. I have some male faston rings on my battery posts to which I connect the trickle charger to and have a small LED battery condition checking meter connected there as well. I also use the "knife switch" type ground disconnect. All of these were disconnected during the last 2 charging attempts.

Any ideas that would shorten my trouble shooting time???

Stu Fox

[Larry M.]

Re: Battery Charging Problem

Stu:

Two areas where I have found similar problems is when my original/mechanical clock contacts closed and stayed shut, and when the diodes in the alternator failed. Both allowed the battery to discharge rather quickly overnight.

With the knife-blade disconnect "open" and everything else electrical in the car shutdown and not in use, see if you have 12 volts on the NEGATIVE CABLE at the knife-blade disconnect. Obviously, the other side of this open disconnect is the negative battery post, which will be at "ground" potential.

If 12 volts is present on the NEGATIVE CABLE at the disconnect, then begin pulling fuses or various connectors until you locate the source of the problem. Again my problems were with a bad mechanical clock and with a bad alternator. It is also possible that your car has a light bulb burning from a bad switch (which cannot be easily seen (like glovebox).

Hope this helps.

Larry

[Stuart F.]

Re: Battery Charging Problem

Larry;

Thanks. My suspicions run with the alternator due to the trouble I had with that connector. My clock has the conversion in it, but I will do an all around check as you suggest.

Thanks again. I knew i could count on my discussion board friends.

Stu Fox

[Donald O.]

Re: Battery Charging Problem

Stu,
If you can get the battery sufficiently charged to 12 + volts AND you have a digital volt/ohm/amp meter, arrange the probes on the meter for measuring amps, and connect between the battery POS term and battery. If there is anything more than a few milliamps on the meter, you have a power line shorting to ground.
Remove one fuse at a time and watch the meter. You may get lucky and see the amp reading drop to nill. If not, disconnect the VR and then the alternator, start with the main red wire and if that doesn't drop it down remove the twin wire plug.
I'm guessing that you have a bad alternator, and it has a short.
If its the original, get it restored, and while its out for the restoration put in a flaps and drive happy. When the original comes back either swap them again or keep the OE in the box and put it on a shelf. I would also send out the VR if original for a restore and put a new modern solid state unit from your flaps in its place.

DonO

[Leif A.]

Re: Battery Charging Problem

Stu,If you can get the battery sufficiently charged to 12 + volts AND you have a digital volt/ohm/amp meter, arrange the probes on the meter for measuring amps, and connect between the battery POS term and battery. If there is anything more than a few milliamps on the meter, you have a power line shorting to ground.Remove one fuse at a time and watch the meter. You may get lucky and see the amp reading drop to nill. If not, disconnect the VR and then the alternator, start with the main red wire and if that doesn't drop it down remove the twin wire plug. I'm guessing that you have a bad alternator, and it has a short.If its the original, get it restored, and while its out for the restoration put in a flaps and drive happy. When the original comes back either swap them again or keep the OE in the box and put it on a shelf. I would also send out the VR if original for a restore and put a new modern solid state unit from your flaps in its place.DonO

OK, I give up, Don...what's a "flaps"?

[Stuart F.]

Re: Battery Charging Problem

In my attempt to do some of the tests you suggested this morning, my meter shot craps - that is the battery shows low as it is an old unit and I could not get the darn back off to change the battery. I did get a check on the 12 volts and it did not read any voltage. Next, I was trying to test the alternator and got no reading either way on the diodes - then my needle started acting up. Guess it's time for me to get into the digital age and get a new meter.

This is the OE on both alternator and VR, but both had been restored some years ago, but not long in service miles - say about 5k. I do have a new alternator bought from Sears years ago, and I have a spare SHP pully which I best get it together. I also have a spare VR.

Thanks for your input, now I'll get a good meter to do some final tests.

Stu Fox

[Vinnie P.]

Re: Battery Charging Problem

OK, I give up, Don...what's a "flaps"?

Favorite Local Auto Parts Store

[Leif A.]

Re: Battery Charging Problem

Favorite Local Auto Parts Store

thank you...couldn't quite decipher that one.

[Stuart F.]

Re: Battery Charging Problem

Further to my posts; I have had my alternator rebuilt by a local shop as the diodes were shot. I don't know exactly what caused the problem, but I suspect it was the loose/disconnected twin wire leads from the VR. As they say, if a condition exists that causes high current to flow through the dodes and cause them to overheat, they will fail - or something like that. The shop did a nice job so I'm going to save this my original alternator in a box on my shelf. I had another set of SHP pullies so I put them on the "033" 55 amp spare alternator I have (it passed the diode test) and I also changed to an aftermarket VR. Everything is re-connected now for a Sunday morning test drive. I checked my battery voltage several times already and it is holding the charge. Incidently, what I learned from this is that the "033" spare alternator I have is a ligit unit used in 63 on C-60 optioned cars (A/C). The VR is a "Sorenson" that I bought long ago and I like the looks of it. My original VR was on the shelf already as I must have found a NOS some time ago.

Good news is that the Restoration Battery did NOT fail, and in fact it withstood 2 complete discharges.

Stu Fox

[John D.]

Re: Battery Charging Problem

My vendor trailer has a 12 volt car battery inside for accessories. Last year I bought a new battery charger at a local auto store. It would not fully charge my 12 volt battery. I suspected that the battery had gone bad. Turns out the new batterry charger only puts out 9.8 Volts. Whew!!!!
So I grabbed an old battery charger and found out it puts out 12.45 or 12.35 volts. I used it to charge my battery and in a short period of time the battery was fully charged.
Now this is not for trickle charging. Just a tip to test your battery chargers to see what kind of voltage they put out.
For testing I have an AC/DC converter. I can dial the voltage to anything I want from O to 24 volts. Also the amps. No more testing with 12 volt batteries and battery chargers. Not accurate enough. Sorry to rob your post Stu. John

[Stuart F.]

Re: Battery Charging Problem

John;

You can jump in anytime John because we know you always have something of value to offer.

Thanks.

Took my Vette out for a test ride yesterday morning. It restarted 3 times very well - even in the morning heat. At home I checked the battery voltage and it was at 13.17 volts. Now I'm concerned my 55 amp alt. and Sorenson aftermarket VR may be overcharging my Restoration battery (AGM type). Concern is that it may overheat it. Have to check with Tom.

Stu Fox

[John S.]

Re: Battery Charging Problem

Stu,

Let us know what he says. I was always under the impression that a 12 volt battery will show 13.1 volts when fully charged.

[Donald O.]

Re: Battery Charging Problem

Stu,

Is the 13.17vdc at the battery with the engine off or running? A fully charged battery should be 12.7 - 13.5 vdc with the engine off, about 14.5 vdc with the engine running and being charged.

Don't be concerned about the higher output that is available when needed from the alternator. I have a 60 amp FLAPS in my 67, the original is 37 amp. I also have a FLAPS electronic VR installed as well. Both of my original units are fully restored and sitting in a box in my fun shop.

If you are concerned about the health of your battery, take it to a FLAPS that will do a free draw down test. The test IIRC is only about 5 minutes

DonO

[Stuart F.]

Re: Battery Charging Problem

13.17 w/engine off. I'm ok with it now. thanks fir the info.

Stu Fox

[Paul J.]

Re: Battery Charging Problem

Volts are only part it. Even a bad battery can show 12+ volts. You need amps to start a car.