f31ixjc

I've had to swap out two batteries over the past year. A couple of weeks ago, I took my 72 to work for two consecutive days and when I got home I couldn't get her to start back up after opening the garage. The starter cranking was super slow and than nothing. Jump starting did nothing either. I finally got around to taking the battery to get checked out at Autozone and after a day of them charging it, they told me it was no good. This was the second battery to die on me since buying this battery. Good thing it has a 5 year warranty.

The guys at Autozone explained to me that if I was leaving the battery connected for long periods of time without driving the car that it would be draining from being grounded and eventually kill the battery.

With the new battery in, she started right up and I brought her into work with me. My questions for you all is:
1.) Would the following explanation from autozone be correct even though I drove the car for two days before it finally died?
2.) Is it more likely the battery is not being charged by the alternator?
--If so, how long would the battery last before dying again?

Any input is greatly appreciated.

FireballXL5

Could always install a battery cut off... Open the connection when sitting? My batt didn't sit through the winter well, so I replaced it with another, but she still cranked slow and sometimes the starter would not function... Took the starter off, and it tested good, but for $47 I replaced it anyways. Put that in and she turns over MUCH faster! Haven't had any starting issues since... The. 'Few' times it wouldn't turn before I was able to knock it with a wooden hammer handle and occasionally get it to go... Which is why I brought it in for testing, thinking it may have a bad solenoid etc... Regardless of it 'testing' good at the store bench, I still replaced it.. Happy camper since!

mrvette

There is no way in hell anyone can test a starter out of the car, or a VERY similar load.....cranking engine...

ALL else is BS.....CASE CLOSED.....

FireballXL5

Yea, figured as much... So basically the napa auto parts bench tests gives it power, makes sure the drive gear engages, spins, and tests amp draw... So, if it doesn't spin, or draws excessive amps... That's all they're testing for right?

Depending on your symptoms of what the starter is 'trying' to do when you turn the key can either point to or eliminate the starter...

But, you also state that the battery is testing bad... Could be just a batch of poorly constructed batteries...?

I'm trying to stay optimistic so you don't go replacing parts in the charging system of the car or diagnosing wiring/grounds...

mrvette

EH, doubtful, what is most likely happening is that the negative terminal goes to the frame just under the battery box......and the engine is grounded to the frame with a ~6" cable leading from the right/pass side of engine to the support on that side.....

obviously to us electronic types those connections need be free of ANY corrosion we drawing serious current now so any corrosion drop voltage to the starter....and it drags under the load.....

NOW to stick a DVM on the AMP/current scale in series with one of the battery posts checking drain when car is in the garage and everything supposed turned OFF.....

IF you have computer FI vehicle you can stand a MAX of 20 ma....that's .020 amps draw and be fine for even a month or so....

if you have a carb vehicle you need to see near zero amp drawn....

7T1vette

Your problem? Buying "Dura-Junk" batteries. A 5-year warranty that sells you 'junk' with the agreement that "If your battery fails, just come on back. We'll give you another one JUST LIKE IT.", doesn't do much for me.

Wal-Mart sells good quality batteries at a decent price with a decent warranty. I've never had to take one back that was in-warranty. Come to think of it, I've never had to take one back!!

You could have a problem with your alternator (also Dura-Junk??) if the voltage regulator built into it is not working properly. If your battery is getting 'over-charged' all the time, it will wear out quickly. Check your battery voltage after you have been driving for a while. Keep car running, with radio and other electrical stuff OFF and measure voltage when engine is at somewhat above idle speed (1000-1500 rpm). It should be getting just over 13 volts. If it is at a significantly higher voltage, the regulator in your alternator is bad....or your alternator is plumbed into your electrical circuitry incorrectly.

C3Hawk

That's what I do with every old car I drive: I disconnect the battery when I park it every night. I've done this ever since I started re-wiring cars and saw what 40 year old wiring looks like! Maybe some day I'll rewire everything 100% but until then I'll just keep using the battery quick dis-connect.

hugie82

Because you got 2 days out of it, I would be checking the external regulator. There's two stages for low rpm and high (above 2300rpm). Sometimes one or the other stage goes and you won't notice until you run it a long time at the faulty stage rpm.
I had an Oldsmobile that every time I cruised down the shore the battery would die but no place else. It turned out the high stage of the regulator was burnt. The 60 mile cruise at 2800 rpm would kill the battery but around town at 1500 rpm would charge no problem.
I know long post sorry....

FireballXL5

^^^ great info. Learn something every day