alt. and battery question
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Pro
Joined: May 2003
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From: Spring Hill Florida
alt. and battery question
hey guys
my alt is about 4 weeks old and it seems like in the daytime with no lights on just my sytem im pulling about 12.5 to 12.9 volts and during the night time with the headlights and fogs on and system im pulling about 13.1 volts... and this is steady it wont just drop and come back up. when i first turn the car when its cold the volts are about 13.9.
is the volt meter in the dash that accurate? if not is it hard to install a aftermarket one
oh also when i see that my volts are a little low i put my battery charger on and it charges some what but when i start driving they go down
does this sound like a drain or any thing or not to worry just keep my eye on it.
thanks for the help :cheers:
my alt is about 4 weeks old and it seems like in the daytime with no lights on just my sytem im pulling about 12.5 to 12.9 volts and during the night time with the headlights and fogs on and system im pulling about 13.1 volts... and this is steady it wont just drop and come back up. when i first turn the car when its cold the volts are about 13.9.
is the volt meter in the dash that accurate? if not is it hard to install a aftermarket one
oh also when i see that my volts are a little low i put my battery charger on and it charges some what but when i start driving they go down
does this sound like a drain or any thing or not to worry just keep my eye on it.
thanks for the help :cheers:
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From: SE NY
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Re: alt. and battery question (Cory00)
It's quite normal for the voltage to be higher just after starting the engine as the starter has put a drain on the battery.
Then it usually settles down to some nominal value after the battery has been charged to capacity.
So long as the voltage stays constant and is over 13 Vdc I wouldn't worry about it.
Then it usually settles down to some nominal value after the battery has been charged to capacity.
So long as the voltage stays constant and is over 13 Vdc I wouldn't worry about it.
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Re: alt. and battery question (65Z01)
It's quite normal for the voltage to be higher just after starting the engine as the starter has put a drain on the battery.
Then it usually settles down to some nominal value after the battery has been charged to capacity.
So long as the voltage stays constant and is over 13 Vdc I wouldn't worry about it.
Then it usually settles down to some nominal value after the battery has been charged to capacity.
So long as the voltage stays constant and is over 13 Vdc I wouldn't worry about it.
You didn't tell us about your battery! How old is it?
On start up, I get 14+ for a few minutes while the alt recharges from the starting cycle, then it drops to 13.6 or so, 13.3 with all things on and at idle
You are in acceptable limits, but I would watch it. Have you cleaned all the connections, battery terminals, etc.?
:seeya
:steering:
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
Re: alt. and battery question (Cory00)
Your dash voltmeter may have some error. Check it by measuring the battery terminal volts with an accurate voltmeter. Normally, the dash voltmeter is 0.3 volts lower than the battery terminal volts. When cold, the alternator puts out 14.7 volts (14.3 v on the dash) and as it warms up it drops to 13.7 volts (13.3 v on the dash).
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Joined: Jul 2002
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St. Jude Donor '12
Re: alt. and battery question (jfb)
Dude, if you still have the original style 17-SI in your '84, with all that stereo, you need to go check out my tech tip on updating to a CS144. That alternator barely kept up with your car stock.
Le Mans Master
Joined: Jan 2003
Posts: 5,858
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From: Santa Maria CA
Re: alt. and battery question (jfb)
Your dash voltmeter may have some error. Check it by measuring the battery terminal volts with an accurate voltmeter. Normally, the dash voltmeter is 0.3 volts lower than the battery terminal volts. When cold, the alternator puts out 14.7 volts (14.3 v on the dash) and as it warms up it drops to 13.7 volts (13.3 v on the dash).
My dash volt meter always shows .3 volts less than at the battery and alternator with a multimeter, idling or not.
[Modified by 86PACER, 1:50 AM 1/2/2004]
