It's died on me three times since Sunday, and I always have to charge it overnight. Looks like the alternator won't charge it either. It's been between like 8 and 10 volts while I'm driving he past few days. Usually it's 13 or more when it's working right. Is the battery dead? Bad cell or something? Or could a wire be lose or something in the car? I don't want to buy a new battery if it's not the problem. Then again, it is a little over 3 years old now...
Is this the sign of a dead battery?
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Opie Knievel
Rum Fueled Midnight Mechanic and Moderator
if it wont hold a charge then its likely the battery. Batteries are rated by both the volts ( should be 13.5-13.7 ) but also by the Amps they can store in energy ( CCA ).
Testing the alternator is pretty simple on these cars. Break out the voltmeter.
Check voltage on the lug on the back of the alternator
A: at rest with the battery hooked up
B: when running with the battery hooked up
C: then running with the positive cable off.
They should all be in the 13.5-13.7 range
A: if less than 13.5 then it could be a discharged battery
B: if less than 13.5 could be alternator or a bad cell in the battery
C: if less than 13.5 your alternator is bad
I think all the auto parts chains will "load" test your battery for free and advise the current CCC rating left in the battery
Testing the alternator is pretty simple on these cars. Break out the voltmeter.
Check voltage on the lug on the back of the alternator
A: at rest with the battery hooked up
B: when running with the battery hooked up
C: then running with the positive cable off.
They should all be in the 13.5-13.7 range
A: if less than 13.5 then it could be a discharged battery
B: if less than 13.5 could be alternator or a bad cell in the battery
C: if less than 13.5 your alternator is bad
I think all the auto parts chains will "load" test your battery for free and advise the current CCC rating left in the battery
Cool, thanks for the step by step procedure, I'll hop on that ASAP. The car is dead in the driveway right now so I'll have to wait for someone else to get home to jump it lol
In order,
1) tried to start the car. It wouldn't turn over. Lights and stuff worked tho
2) tested the battery with car off. 11.28V
3) tested battery negative nut and alternator lug, car off, 11.28V
4) jumped it with someone else's car. Tested battery negative nut and alternator lug. 11.25V. Car was running.
5) shut the car off. Tried to start it 2mins later and it wouldn't turn over.
So I guess that battery has reached the end of its life? Is 11.28 volts not enough to get a car going? Not sure how to test CCA unless I went to the auto store in town. My multimeter doesn't test DC or AC volts above 10, and I thought car batteries were usually in the hundreds, like 500-900 CCA somewhere.
1) tried to start the car. It wouldn't turn over. Lights and stuff worked tho
2) tested the battery with car off. 11.28V
3) tested battery negative nut and alternator lug, car off, 11.28V
4) jumped it with someone else's car. Tested battery negative nut and alternator lug. 11.25V. Car was running.
5) shut the car off. Tried to start it 2mins later and it wouldn't turn over.
So I guess that battery has reached the end of its life? Is 11.28 volts not enough to get a car going? Not sure how to test CCA unless I went to the auto store in town. My multimeter doesn't test DC or AC volts above 10, and I thought car batteries were usually in the hundreds, like 500-900 CCA somewhere.
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11.28 volts with the car running? Then your alternator is not charging. Shouldbe over 12 volts, like 13, 14 volts. Your battery was not charged enough in two minutes. To test amps you need an amp meter or load tester. A way to test your altinator is, when engine is running take the positive cable off the battery. If the engine stays running then your altinator is putting out enough voltage to keep the car running. Then take the battery some were and have it tested. Hope this makes sense and good luck.
You think you could borrow a battery load tester from your autoparts store? That would give you a quick answer. It definetly sounds like a bad cell in the battery to me. This isn't an AGM battery correct?
did you test it at the alternator with the positive cable off the battery and the car running ?
Just running the car with the positive terminal unhooked is indeed a quick test to see if it produces enough current to keep the coil fired but without a measurement of its output you have no way to know if its adequate to charge your battery while powering all your accessories in the car. A dead cell in the battery could pull down the output from your alternator.
If you find the output is down on the alternator try to find a local place that rebuilds them. Its typically cheaper and they do a better job then the big box stores. If they are waist deep in starter and alternator cores you are in the right place
I know they guy by me charges $110 with a 1 year warrenty
Just running the car with the positive terminal unhooked is indeed a quick test to see if it produces enough current to keep the coil fired but without a measurement of its output you have no way to know if its adequate to charge your battery while powering all your accessories in the car. A dead cell in the battery could pull down the output from your alternator.
If you find the output is down on the alternator try to find a local place that rebuilds them. Its typically cheaper and they do a better job then the big box stores. If they are waist deep in starter and alternator cores you are in the right place
I know they guy by me charges $110 with a 1 year warrenty
Your battery is not the culprit of your issues based on the info you provided above. It may be worn out and in need of a replacement, but #4 above means your alternator is bad or you have a wiring issue. If your battery was the issue and the alternator and wiring were good, then it would be charging in the 14-16 range. Comment 4 means you NEED an alternator if you charging light in the dash is functioning.
Regarding your question of 'is 11.28 volts not enough to get a car going', the answer is yes and no. Voltage plays a very small role in getting the starter to turn the motor over - amperage (power) is what turns the motor over. The only way, that I know of, to check a battery's amperage is to load test it. Obviously you've discovered that 11.28 volts wouldn't start your motor, but a good battery (with plenty of amps) will start it at 10.5 volts. There is a correlation between amps and voltage in a car charging system due to how the system is designed and functions, but not in most other situations. Think about a little 9 volt dual post battery that runs bunches of SMALL handheld electrical devices. If you hook two of them up in series, then you have 18 volts, but obviously they will not start your motor. Amperage is what is needed. Any way - enough of that.
When you take the alternator out, check all connections and wiring at the alternator, starter, block, and battery. Repair anything that is loose, overly corroded or melted. Good luck - Jim.
p.s. - do you have an idiot light or voltmeter in the dash?
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