Battery problems

[DukeOfEarl]

I have a 4 month old better in my 2003 Z06 and have not started the car for 2 weeks.
When I went to start it it would not turn over but the lights worked.
Then I had it jumped but all I gotr was click click click.
Afer he left the charger on the car it started and went to 14 volts before going back to 13.
Could the security system have anytging to do with it if the car was no running a couple of weeks.?
Also where my ignition swith is the black ring around it is loose.
No lights were left on the car so that was not the problem.
One more thought about 3 weeks ago when I went to start it my computer said charging system fault
because I left my detector on. My detector shuts automatically when the car is not running.
Is it normal if you dont start the car after 2 weeks for the battery to drain.
Any thoughts?

 

[LLC5]

I have a 4 month old better in my 2003 Z06 and have not started the car for 2 weeks.
When I went to start it it would not turn over but the lights worked.
Then I had it jumped but all I gotr was click click click.
Afer he left the charger on the car it started and went to 14 volts before going back to 13.
Could the security system have anytging to do with it if the car was no running a couple of weeks.?
Also where my ignition swith is the black ring around it is loose.
No lights were left on the car so that was not the problem.
One more thought about 3 weeks ago when I went to start it my computer said charging system fault
because I left my detector on. My detector shuts automatically when the car is not running.
Is it normal if you dont start the car after 2 weeks for the battery to drain.
Any thoughts?

You need to start with the basics, make sure that your battery cables are clean and tight (making sure that the cables do not twist after tightening the cable bolt). Then have your battery load tested properly to make sure that it is good, remember that a fully charged battery does not mean that it is good, only that it is ready to be load tested. If all is good with your battery and cables, then have a full charging system check done to make sure that you are getting full output from your alternator. With a good battery, clean and tight cables, your voltage should be about 13-13.5V with ALL the accy's on and rpm's about 1500-2000 rpm's. If everything is fine, than a parasitic draw is possible pulling the battery down while sitting, but after 2 weeks that would usually result in a totally flat battery with no/little voltage left. Good luck with it.

 

[BigJimZ16]

To add to what LLC5 said, I've seen several replacement side post batteries that the bolt hole is NOT as deep as the original; so that when the battery cable is torqued to spec, the bolt bottoms out and the cable is still loose!

Good luck making your Z hum!

 

[DukeOfEarl]

LLc5 Thank You

You need to start with the basics, make sure that your battery cables are clean and tight (making sure that the cables do not twist after tightening the cable bolt). Then have your battery load tested properly to make sure that it is good, remember that a fully charged battery does not mean that it is good, only that it is ready to be load tested. If all is good with your battery and cables, then have a full charging system check done to make sure that you are getting full output from your alternator. With a good battery, clean and tight cables, your voltage should be about 13-13.5V with ALL the accy's on and rpm's about 1500-2000 rpm's. If everything is fine, than a parasitic draw is possible pulling the battery down while sitting, but after 2 weeks that would usually result in a totally flat battery with no/little voltage left. Good luck with it.

LLC5 Thank you.
I had the battery checked since it is only 4 months old. The negative cable was about
1/4 of a turn lose. Tightened it up but my battery guage still was only 13.2 and 4 while driving.
I put on all power options and it went to 12.9
I do have a 383 stroker motor in it and it has an underdrive pully so I though maybe that has something to do with it.
Also my computer read 13.3 volts at idle but the garage who did a battery check saidd I was at 13.8 volts.
I wonder if my guages are off.
Thanks again

 

[DukeOfEarl]

Battery

You need to start with the basics, make sure that your battery cables are clean and tight (making sure that the cables do not twist after tightening the cable bolt). Then have your battery load tested properly to make sure that it is good, remember that a fully charged battery does not mean that it is good, only that it is ready to be load tested. If all is good with your battery and cables, then have a full charging system check done to make sure that you are getting full output from your alternator. With a good battery, clean and tight cables, your voltage should be about 13-13.5V with ALL the accy's on and rpm's about 1500-2000 rpm's. If everything is fine, than a parasitic draw is possible pulling the battery down while sitting, but after 2 weeks that would usually result in a totally flat battery with no/little voltage left. Good luck with it.

LLC% just left another post.
I just started the car and now reading 13.8 and on full load 13.6 till I idle then it goes to 13.2 or 3
so maybe just friving it charged it up
Thanks again

 

[LLC5]

LLC5 Thank you.
I had the battery checked since it is only 4 months old. The negative cable was about
1/4 of a turn lose. Tightened it up but my battery guage still was only 13.2 and 4 while driving.
I put on all power options and it went to 12.9
I do have a 383 stroker motor in it and it has an underdrive pully so I though maybe that has something to do with it.
Also my computer read 13.3 volts at idle but the garage who did a battery check saidd I was at 13.8 volts.
I wonder if my guages are off.
Thanks again

Has the battery been load tested since your problem? Battery's can be bad right off the shelf when you buy one new.

The cables are clean tight and you cannot twist them side to side, correct?

13.2 and 13.4V is good, 12.9 is low. What rpm's did you notice the 12.9V?

Your gauges could be off a little, but you need a Tech 2 scanner to calibrate them, and more importantly someone who knows how to do it properly. Double check your voltage readings with a quality voltmeter connected to the battery terminals, this will be the real voltage and let you know if your gauge is off. Good luck with it.

 

[DukeOfEarl]

Has the battery been load tested since your problem? Battery's can be bad right off the shelf when you buy one new.

The cables are clean tight and you cannot twist them side to side, correct?

13.2 and 13.4V is good, 12.9 is low. What rpm's did you notice the 12.9V?

Your gauges could be off a little, but you need a Tech 2 scanner to calibrate them, and more importantly someone who knows how to do it properly. Double check your voltage readings with a quality voltmeter connected to the battery terminals, this will be the real voltage and let you know if your gauge is off. Good luck with it.

LLC% thank you for the good advice. I may have the altinator tested Monday.
But funny now I am at 13.8 volts just strted again a few minutes ago.

 

[LLC5]

LLC% thank you for the good advice. I may have the altinator tested Monday.
But funny now I am at 13.8 volts just strted again a few minutes ago.

Alternator problems are rare. Your charging system fault message and starting problem could be from the loose battery bolt, and the 12.9V could be from the under drive pulley. I would clear all the codes and see if any come back with the cable tight. The ECU controls the voltage at the battery, so when you start your car cold you may see 14-14.2V then taper to 13.5-13.8V, which is normal operation to help keep the battery from gassing when hot and of course a small benefit in fuel consumption. Good luck with it.