Partial battery snafu - should I worry?

Gogar · 06-29-2009, 03:38 PM

I've been driving the '72 quite a bit, everything seems to be getting better and better since I got it back together.

ANYWAY, yesterday I drove 3 or 4 different places, each for an hour or two. SOMETIME before my last stop, the HEAVY battery cable that goes directly to the starter came loose from the positive battery terminal. (I doubt it touched a ground or the body anywhere. Lots of carpet and rubber up there.)

(preface) I have converted to a one-battery setup - so I have ONE big thick cable to the starter, and then another smaller-gauge wire running (I assume) other stuff.

Anyway, I came out and the solenoid clicks, but of course the starter does not turn. I push-start the car and drive home (10 minutes). When I get home, I check the battery running and not, and it's right around 12V. Not so good.

In my haste to check voltage, I didn't even SEE that the big wire wasn't connected. Yeah I know.

So, threw it on the charger. Came back later, noticed the big wire, hooked back up, battery charged. Everything's great. Charging fine, running fine.

Is there anything else i should check to make sure I didn't fry something?

I'm thinking if everything works then I'm okay.

TIA

304065 · 06-29-2009, 04:09 PM

I don't completely understand, the positive battery terminal came off and you drove around like that, draining your battery by running the ignition and accessories off it?

Well, when the positive terminal came off, the alternator was suddenly without a load. This tends to fry diodes, regulators etc. Likewise you killed the battery down to +12V. Starting batteries don't like to be deep-cycled like that, they are designed for a long cranking period and maybe a 3% discharge, not a 75% discharge (which is what 12V is).

Charge the battery for three days nonstop and see if it holds a charge.

Measure the battery voltage with the car running and report it back here.

Monitor closely with one of those cigarette lighter voltmeters for any low charging voltage, you could be OK, but telling a guy with an '83SC that "you could be ok" that his electrical system is "probably fine" is like telling a guy who just got struck by lightning that he could be OK!

Gogar · 06-29-2009, 04:17 PM

Quote:

Originally Posted by john_cramer

I don't completely understand, the positive battery terminal came off and you drove around like that, draining your battery by running the ignition and accessories off it?

Not really. On the positive battery terminal (Car is a '72T, I have removed the second battery) there are TWO things: the big fat copper wire that goes directly to the starter, and a smaller (maybe 12 gauge) wire. ONLY the big 'starter' wire came loose.

So, I'm assuming that this (loose cable) issue only happened on my last stop, when my starter wouldn't turn over and I push-started and drove 5 minutes home.

So, since figuratively there was still a positive connection (albeit not the greatest) I'm wondering if I dodged the bullet you're talking about.

Thanks!

Gogar · 04:27 PM

My voltage today is 12.54. Yesterday when this happened, I but the battery on the charger for an hour or two when I got home, as I discovered the problem. After I found it, I charged the battery for a while longer, and started. My charging system seemed to be working fine. Voltage was 13.x at idle and a bit under 15 under revs.