Tech Help/Battery/Electrical
Thread Starter
Racer
Joined: Jun 2004
Posts: 313
Likes: 0
From: Macomb MI
Tech Help/Battery/Electrical
Today was a reasonably decent day in Michigan so I decided to go the the mini-storage where I keep the 91 Coupe. It has been there since early November. Battery was dead. No electrical outlet to plug in trickle charger. Jumped it, and took it out for a several mile (25 or so) drive to get some life back. The guage indicated a steady 12+ volts while I was driving and idling. Back to the storage building, shut down, and tried to start but no power. Battery was replaced last summer. Alternator is ok. Looking for your thoughts.
Thanks,
Jim
Thanks,
Jim
Race Director
Joined: Jan 2006
Posts: 10,039
Likes: 0
From: CA
12+ volts is too low.You said your generator is OK.How do you know?Did you check the output with a VOM at the generator? Voltage should be around 13.5 to 14 volts depending on the state of the battery.If you've got that voltage at the generator,then it is losing it somewhere in between it and the battery.
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Jim,
You may have a problem with the alternator.
The voltage while driving should have been 14+ volts, not 12+.
Even though the battery is only 1 year old, pull it, have it tested, as a possible reason for the low voltage is a shorted cell.
however,
Unfortunately, I suspect the alternator has failed.
So, if the battery checks out ok, pull the alternator and have it checked/replaced.
You may have a problem with the alternator.
The voltage while driving should have been 14+ volts, not 12+.
Even though the battery is only 1 year old, pull it, have it tested, as a possible reason for the low voltage is a shorted cell.
however,
Unfortunately, I suspect the alternator has failed.
So, if the battery checks out ok, pull the alternator and have it checked/replaced.
Drifting
Joined: May 2004
Posts: 1,543
Likes: 1
From: Levittown NY
Sounds like your battery is toast. Bring it to a autozone or similar and they can test it for free. Driving your car with a dead battery is a nice way to kill your alternator. Why don't you remove the battery from the car and keep it where there is an outlet so you can put on a tender (not a charger) during storage?
Thread Starter
Racer
Joined: Jun 2004
Posts: 313
Likes: 0
From: Macomb MI
Thanks for the ideas. I disconnected the battery before I left it in storage. It most likely will be April before it reappears. May take the advise and pull the battery for testing after I bring it home and charge it for seveal hours, then let it set a few days.
I have replaced the battery 3 times and the alternator twice in the four years I have owned the car. The good news Sam's replaced the battery free, and a Chevy dealer in Indianapolis did the 2nd alternator free.
About the only thing I won't do is buy another Interstate Battery. See below.
http://forums.corvetteforum.com/show....php?t=1031134
Thanks to all.
Jim
I have replaced the battery 3 times and the alternator twice in the four years I have owned the car. The good news Sam's replaced the battery free, and a Chevy dealer in Indianapolis did the 2nd alternator free.
About the only thing I won't do is buy another Interstate Battery. See below.
http://forums.corvetteforum.com/show....php?t=1031134
Thanks to all.
Jim
Drifting
Joined: May 2004
Posts: 1,543
Likes: 1
From: Levittown NY
Thanks for the ideas. I disconnected the battery before I left it in storage. It most likely will be April before it reappears. May take the advise and pull the battery for testing after I bring it home and charge it for seveal hours, then let it set a few days.
I have replaced the battery 3 times and the alternator twice in the four years I have owned the car. The good news Sam's replaced the battery free, and a Chevy dealer in Indianapolis did the 2nd alternator free.
About the only thing I won't do is buy another Interstate Battery. See below.
http://forums.corvetteforum.com/show....php?t=1031134
Thanks to all.
Jim
I have replaced the battery 3 times and the alternator twice in the four years I have owned the car. The good news Sam's replaced the battery free, and a Chevy dealer in Indianapolis did the 2nd alternator free.
About the only thing I won't do is buy another Interstate Battery. See below.
http://forums.corvetteforum.com/show....php?t=1031134
Thanks to all.
Jim
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You must not frequent the forum. I have posted many many times the information that lead acid batteries should not be left sitting for long (4+ weeks) periods. Lead acid batteries self discharge up to 1% each day even disconnected and as they discharge lead sulfate collects on the plates. If recharged in a short time, the lead sulfate converts to lead and sulfuric acid. If left sitting, the lead sulfate goes from soft to hard and then it cannot be converted and lead sulfate is an insulator. A fully sulphated battery cannot supply current nor will it accept charging current and is a door stop. If you store your vette where no 120v is available, or sunlight is available for a solar battery charger, then take the battery out and put it on a battery tender which is a smart charger that measures the battery voltage and charges the battery when it detects a 10% drop and then turns off.
Thread Starter
Racer
Joined: Jun 2004
Posts: 313
Likes: 0
From: Macomb MI
You must not frequent the forum. I have posted many many times the information that lead acid batteries should not be left sitting for long (4+ weeks) periods. Lead acid batteries self discharge up to 1% each day even disconnected and as they discharge lead sulfate collects on the plates. If recharged in a short time, the lead sulfate converts to lead and sulfuric acid. If left sitting, the lead sulfate goes from soft to hard and then it cannot be converted and lead sulfate is an insulator. A fully sulphated battery cannot supply current nor will it accept charging current and is a door stop. If you store your vette where no 120v is available, or sunlight is available for a solar battery charger, then take the battery out and put it on a battery tender which is a smart charger that measures the battery voltage and charges the battery when it detects a 10% drop and then turns off.
Jim
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Melting Slicks
Joined: Dec 2004
Posts: 2,954
Likes: 2
From: Obama=death for America
If you are going to continue to do to your battery what you have been doing, I suggest that you get a Red Top Optima. They are made for and can more easily withstand the constant draining that you are doing/ putting on it. The best thing you can do is to remove your battery and keep it on a tender/float charger until you're ready to drive your car.
If that's too much of a pain, get the Red Top.
I agree with you about the Interstate. I had one and it sucked.
If that's too much of a pain, get the Red Top.
I agree with you about the Interstate. I had one and it sucked.
Thread Starter
Racer
Joined: Jun 2004
Posts: 313
Likes: 0
From: Macomb MI
If you are going to continue to do to your battery what you have been doing, I suggest that you get a Red Top Optima. They are made for and can more easily withstand the constant draining that you are doing/ putting on it. The best thing you can do is to remove your battery and keep it on a tender/float charger until you're ready to drive your car.
If that's too much of a pain, get the Red Top.
I agree with you about the Interstate. I had one and it sucked.
If that's too much of a pain, get the Red Top.
I agree with you about the Interstate. I had one and it sucked.
I think you are right. It's a pain to remove, but the best idea. This year, between bad weather and a few weeks in the hospital, I drove the Corvette less than 500 miles.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Red Top batteries are lead acid batteries with a gel electrolyte and they are no different with regards to letting sit idle. Lead sulphate forms on their plates too. All lead acid batteries should be kept fully charged or they lose amp-hour capacity until they are no longer a battery (fully sulphated).
Le Mans Master
Joined: Mar 2002
Posts: 5,889
Likes: 2
From: Castro Valley Calif.
St. Jude Donor '03 thru '26
Here's what I think is happening. You're in a cycle which is ruining your battery and, that in turn is ruining your alternator. 12 volts back is too low......there's a better than average chance your present alternator is toast (check it per post # 2 when you next get the car started). In the future, I bet if you pulled the battery and took it home to a tender during those long storage periods and had a good alternator to start with, your electrical problems might be over. 
