About a month ago I took the car out for a drive.  Everything ran great, made several stops, nothing unusual in regards to starting or running.  Parked it in the garage and it sat for about two weeks.  A week or so ago thought I'd take my younger daughter to school in it and then drive it to work.  Tried to start it - nothing.  Not even a solenoid click.  I think battery voltage was only like 2 volts or something.  Put the 2 amp charger on it for a couple of days and the green light came on indicating everything was A-OK.  But voltage was only showing 11.5.  Enough to turn the motor over 1/2 turn, but that was it.  The battery is less than a year old, it's an interstate from Costco.  Just a battery or something worse?  I could go get a new battery from Costco, but probably not an effective method of troubleshooting.  Major electrical drain?  My factory alarm system does work (at least it did) but I know they can be problematic with drain.  Until now I really haven't had any drain problems - car could sit for two months and still start no problem.  Alternator or regulator?  At a loss here.... thanks

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You will need to disconnect the battery and put a volt ohm meter between the cable and the battery terminal and measure the current draw when everything is off. If that is just a few milliamps, then your battery is probably bad. You can take your battery to most auto parts stores and get it tested for free though before you return it.

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1973 L-82 4 spd

Charge the battery, and then take it to have it tested. It has to be fully charged to get a reliable test result. A lot of things on these cars can drain a batt overnight, or over a few days, including the clock, a bad alternator, interior light left on, the alarm relay, etc. Start with the basics, and verify the battery is good before doing anything else. 

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Joel Adams
C3VR Lifetime Member #56    
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Thanks guys. Battery on charger now (again) and will take it. In this weekend to have it tested . We shall see !

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Dave - +1 on getting the battery tested then testing the system for draw with an ohm meter. Usually any kind of spark when you connect the last cable is a good indicator of current draw. 

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John Sigmund

Just a quick caution with the volt/ohm meter suggestions...   I'm guessing this is what is also called a multi meter, make sure you have it set to the highest Amp scale it has (usually 10 Amps) before connecting it in line between the battery post and the cable normally connected to that battery post.

If it's on ohms, you will instantly fry the meter.  Poof !!

If it's on volts, it will happily tell you a voltage of some sorts, and not destroy the meter, but not helpful.

If on the 10 Amp scale you only get a small or negligible reading, then drop down the scales in turn until

a reading is present. This is all key off of course, and don't turn the key at any time.

Also, while you have one meter probe connected to the +12V batter post and the meter is on any Amps/millAmps  scale, do not let the other meter probe accidentally touch a metal part of the car or POOF - no more meter !!

Cheers

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Kiwi Chris

Once you've determined the battery is good, disconnect the negative battery cable and run a test light between the negative post and the cable end.  The test light should illuminate.  Then remove one fuse at a time until the light goes out.  When that happens you've isolated the circuit the battery drain originates from.  Then you can determine what part of the circuit the problem lies.

Thanks, John.  I've had a cut-off switch installed for several years now (it's actually a decent one) but I don't typically have to use it, even if I won't drive the car for a month.  Going to be looking for some sort of drain.  

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Thanks - yep I know about the concerns about testing current draw with the multimeter.  Mine you have to move the red lead to a different terminal if you want to test on the 10A setting.  Even then if it's drawing anywhere close to that you can only let it operate at that current for a matter of seconds, I think.  Will be careful...thanks.  



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No courtesy light timer on mine.  It is possible the interior lights were on all night, but it's unlikely.  It's parked in our garage right now where I see it all the time at night versus my shop where it usually lives.  But possible.  Doesn't take much for a door switch to fail and go to ground which turns on the lights.  Alternator is definitely a possibility too.  It's a reman that I bet is more than 10 years old.  Or the alarm relay.  Or something else.  Or it could just be the battery with no drain.  I'll be looking into it later this week.  Thanks for the suggestions.  



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Dave, I had a '77 in the shop years ago that had a battery drain issue that eventually turned out to be the courtesy light switch on the passenger side. Had a hard time finding it because the car only had ONE interior light that worked to begin with. Turns out someone had replaced the switch with the wrong one(too short), and it was keeping the light circuit on all the time. Sometimes a door left partially open with a so-so switch will do the same thing.
I'd still start with having the battery tested, then the alternator, and then go from there.

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Joel Adams
C3VR Lifetime Member #56    
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

For anyone that is interested, here is a pretty decent article on Testing for parasitic battery drains...


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Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

My parasitic drain turned out to be my center glove box light.  The lid wasn't pushing the plunger far enough.  I discovered that on a dark winter afternoon.  I could see light coming out around the edges of the lid.  Did a bubba fix on it and all is good.  Also have a disconnect of the battery itself.

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Winter! In Texas! In May? Musta been a DARK nite, or a BRIGHT lite. 😈😀 LOL!

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Click on image for full view

Well, sunset probably isn't as early as your's but it's darker a 5pm in November than it is now. 

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If the battery was drawn down to 2 volts then there was a drain of some sort.... however, if it charges up to 11.5 volts then there is a cell that has gone bad.  Each cell provides about 2.2 volts .  Costco batteries are usually the heaviest batteries that Interstate carries. Though I don't advocate using the heaviest battery available, at least in our cars(C3's) the battery is not located in the engine compartment, so heat is not a factor in the life of these batteries.  I have seen Costco bad batteries in the pile that were not very old.  As the boss usually says about some of our batteries "Two pounds of 'stuff' in a one pound bag".   Otherwords, the higher output batteries have more plates in them to obtain higher cranking amps, which is ok given that its not in the engine compartment, otherwise the heat from the engine would severely shorten the life of the battery. 

have the battery checked then go from there to find a drain.... :)

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StingrayJim
NCM Lifetime Member #1936

Stingray's '76���������������������������� StingrayJr's '78���������������������������Lil Red '94

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Thanks everyone, but after some checking today I don't think there's a drain.  Or if there is, it's intermittent.  

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Thanks for the additional info, Jim.  That 2 volts may have been wrong, but I'm not sure.  My voltmeter may have been acting up.  It did definitely come up to full charge, though.  When I was exchanging it, Costco asked if it was a "bad cell" and I did just say yes.  So is there something about that battery that would not work well with our cars?  It's a group 78, CCA 800, CA at 32 degrees is 1000.  

|UPDATED|5/23/2016 6:21:41 AM (AZT)|/UPDATED|


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i went through 3 battery is three years.  Each died almost to the day a year later.  Always a bad cell.  All through Advance Auto/ Western Auto.  Last battery I got has now lasted, knock on wood, 7 years.  All were high quality, so I thought High dollar batteries.  Found out there was a manufacturing flaw according to the sales guy that they were replacing a large number of batteries.  They tried charging me for the prorated deal but managed to persuade them not to

My drain turned out to be the alternator.  Posssibly a blown diode allowing reverse current flow.