The wierdest battery problem I've ever seen

I've got one of thoes "repro" delco batteries. ou: .

Anyhow, I keep it on an automatic battery charger because we haven't been driving the Riv very often lately. I've noticed over the past couple weeks the pointer on the battery charger guage wiggling a lot while on charge. uzzled: I just blamed it my house wiring.

So today we took her for a 120 mile trip. I noticed the ammeter in the dash flickering between "0" and "charge" going nuts all the while we were driving! :eek2:

So when we got home, I checked the batt cables, they are both clean and tight. Same for the alt wires and the grounds.

Just for the heck of it, I disconnected both battery cables (to isolate the battery) and connected the battery charger, and that needle is still going berserk. I then tried another charger, same thing! :error:

I know my repro battery is junk, but it still starts the car OK. My wife is afraid it's going to explode or something. Anybody else ever seen this phenomenon before? o No:

 

No, I no longer have the instructions. But even if the flickering is b/c it's fully charged, that doesn't explain the unstable charging rate when it's connected to the cars electrical system.

While driving yesterday I tried adding load by putting the fan on hi and turning all the lights on, and the dome lights began flickering at the same rate as the ammeter. I have a 80 amp alt, so it pegs the needle pretty good when sends high current back to the battery. :Brow:

It almost seems to me like the battery has an intermittent internal short. uzzled:

 

Do you know that the voltage regulator is basically an on-off device?

-Bob C.

 

The flickering or pulsing usually occurs when high resistance has been introduced into the electrical system. I would suspect the firewall plug connection first and then the fuse panel. See if it changes when your assistance wiggles or puts pressure on the connector. If so clean the contacts.

 

I have experienced this before, it means ur battery is junk. It happened to my battery, i left the car alone for abouta month, no starting. And then i had to jump start the car. The alternator wasnt charging at the time so it was alot of jump starts. When i charged the battery, it did as you described, but i would only get 2 or 3 starts out of it before it died. (i didnt have an ammeter though, so i cant relate to that part). The guy who tested the battery told me it had been overcharged too many times, and i cant remember but he said something like, it had too many volts and not enough amps, or the other way around. Not sure what that meant, but it had been overcharged too many times. It was a refurbished one, so they replaced it under their 1 year warranty.

 

This is interesting!!! I have a problem like you have. The problem I have is the amp guage wiggles wile the car idles. I was told this was because of alternator or regulator and or ground problems (wire harness, alternator and regulator new) . Well the inside lights and outside don't stay constant and get bright and dark (just noticable) with the car not running. The battery cranks the engine like the spark plugs are out so it has the cranking power. The battery is over 5 years old and this may be the problem on my car and a bad battery may be the problem on you car, AL.

 

I forgot to add this problem is not with my 72 GS but my 68 Corvette, AL.

 

Larry.......I'm running the 78A internally regulated one. Here's the real topper........batt voltage (after removing the surface charge) is 12.8 volts. Cell to cell voltage is about 2-2.2 volts per cell. My hydrometer shows all cells to be equally fully charged. The charging voltage with the motor running is 14.2 volts. What's even more wierd, today I took it for a 1 hour drive and the needle stayed steady until I just about pulled into the driveway. I yanked field wire and the pointer settled down in the "D" zone as I expected it would. uzzled: I'm going to try a different battery and see what happens later this week.

I should add that this battery is the same one I was complaining about last year b/c it had a weak cell. (it was only 2 years old) Since then I purchased an electronic "de-sulphator" which I left connected to the battery over the winter. It actually worked, as the weak cell has come back. Before doing that that battery would only crank for about 30 seconds and just die out. Now it will crank for nearly 2 or 3 minutes. I just don't see how a battery that checks so good could be causing trouble. I just might try a different alternator too just for the heck of it.

 

If a new battery solves your problem I will do the same, AL.

 

I would suggest to anyone with an old car or battery lawn motor for that matter to get one of those small "smart Chargers" They just have a red and green light that tells you if it is charging or just in storage mode. It is a very slow charge when on and will not over charge as it turns itself off. I kept a Delco repro battery alive for 9 years with one of these. I think they are about 50-60 bucks.

 

Thanks for the post. See that these are on back order and a 30+ day wait is in effect. Have the page bookmarked as a favorite and will keep checking in. Sounds like a good thing and your using same over the last 5 years makes it even better. Jim

 

Well, it wasn't the battery.

So I tried another alternator, and presto! Problem gone. Being the inquisitive person that I am :Smarty: I took this problem one step further.

There are a few different parts inside an alternator that could fail. The most likely culprit here would be the regulator. Just to prove to myself that it was the internal voltage regulator that had the gremlin in it, I re-installed my original alternator except with a known good voltage regulator. Problem is still gone! So that was in fact the whole problem, it was the internal voltage regulator.

Al, if I were you, since you have the same problem, I'd spring for a new alternator. :beer

 

I am surprised you didn't mention in your original post that you'd changed to an internal regulator. It sounded like your setup was stock except for the "repro" battery.

Why do you have a 78A alternator? The more amps, the more you will notice a flickering.

Also, as you know, you can replace the voltage regulator without replacing the alternator. When these get rebuilt, they install the cheapest regulator they can find- typically these have a lot of variation to their target voltage (i.e. some aim for 13.7, some aim for 14.2, some aim for 14.7, etc.). Because I run FI and my system is very sensitive to voltage, I sprang for an AC-Delco regulator- these cost a lot more (almost the price of a whole alternator if i recall correctly), but have a much more consistent voltage from unit to unit.

I have learned a whole lot from MAD (http://www.madelectrical.com/) - that guy is a real gift to the car community. When I called him about a relatively simple problem, he was SO happy to teach me a LOT of stuff that I never knew. Smart guy!

-Bob C.

 

8 years ago I bought a Sears Die Hard Gold battery for all of my cars. I leave them in my cars and charge them once or twice over the winter because I just don't have time to deal with it. So far this year I have replaced 3 of them so they seem to last 8 years even with lack of attention.

 

I have a external regulator on my 68 Corvette. I tried looking for a new Delco Voltage Regulator but I was told the Delco has discontinued making them so I'm scewed! I will check to see if there are any companies that rebuild the old external style voltage regulators, thanks for your follow up :beer , AL.

 

Bob, good point! If anyone needs any of the newer alternator parts I have them, but as I posted the old Delco regulators have gone "by-by", AL.