Optima / what Volts
Thread Starter
Instructor
Joined: Sep 2005
Posts: 222
Likes: 1
From: Brenham Texas
Optima / what Volts
Well my one year old Optima failed to start the vette yesterday.
Took it to Autozone, they said they had to charge it first. Like 12 hours.
Went back this morning and they told me it charged up to 12.5 volts.
Put in back in the car ran it around getting these volt reading.
And had the Charge sysytem fault come up.
With just the key on 11.6 volts running 13.4 sometimes drops to 12 or lower.
What do you think ?
Battery or not.
Thanks
Took it to Autozone, they said they had to charge it first. Like 12 hours.
Went back this morning and they told me it charged up to 12.5 volts.
Put in back in the car ran it around getting these volt reading.
And had the Charge sysytem fault come up.
With just the key on 11.6 volts running 13.4 sometimes drops to 12 or lower.
What do you think ?
Battery or not.
Thanks
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Actually volts will give you some idea of what is going on.
On a fully charged battery the voltage should be 12.8 Volts.
If it has been charged and is not near that the battery probably has a faulty cell.
When running your alternator should be putting out about 13.8V or more.
Sometimes at idle with all the accessories on it will drop below that on some cars.
Autozone has a charging system tester that will tell you if your alternator is working correctly (while on the car) and they can test the battery also.
On a fully charged battery the voltage should be 12.8 Volts.
If it has been charged and is not near that the battery probably has a faulty cell.
When running your alternator should be putting out about 13.8V or more.
Sometimes at idle with all the accessories on it will drop below that on some cars.
Autozone has a charging system tester that will tell you if your alternator is working correctly (while on the car) and they can test the battery also.
Race Director
Joined: Jan 2006
Posts: 10,554
Likes: 33
From: Not on either liberal coast.
Have your alternator checked as well. I know of a local guy who complained about his batteries going bad...turns out his alternator is the real culprit, not the batteries.
He's a shade tree mechanic who installed headers on his car and in the process apparently damaged the alternator (diodes or something internally?)...100 new batteries won't last long if the alternator isn't doing its job. He knows now why it's recommended to disconnect the battery when doing engine work. I'm taking the message to heart as well...
He's a shade tree mechanic who installed headers on his car and in the process apparently damaged the alternator (diodes or something internally?)...100 new batteries won't last long if the alternator isn't doing its job. He knows now why it's recommended to disconnect the battery when doing engine work. I'm taking the message to heart as well...
Last edited by hotwheels57; Aug 12, 2006 at 02:40 PM.
