Is this the normal battery voltage level when driving

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Aug 2, 2006 | 04:43 PM

raztek

Thread Starter

Burning Brakes

Joined: Feb 2006

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Is this the normal battery voltage level when driving

I've noticed that my battery voltage when driving is around 12.7 volts (when all accessories are on) and around 13.0 volts with them off. I wanted to know if this was normal. I don't think it is as I remember a higher reading previously on the car. Is this an indication that the alternator is on its way out? I can't remember if it normally charged at 14+ volts or not. I had a Catera previously and know that 13 volts was the normal standard charging voltage in Europe, but I'm in Canada and it should be charging at 14 volts, no? I have a 2000 Coupe.

Thanks in advance for shedding light on this for me!

Aug 2, 2006 | 04:52 PM

C5XTASY

Safety Car

Joined: Oct 2000

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From: Monticello MN

Quote:

Originally Posted by raztek

Mine runs 14.2-3 when charging and 13.7, or so, as I remember,when charged (with the car running). I believe you have a proiblem. Are you sure you don't have a battery cell on the way out? Worth checking as that would be cheaper than an alternator. Good luck to you!

Aug 2, 2006 | 05:04 PM

raztek

Thread Starter

Burning Brakes

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Thanks Ed, I'll check it out, but I replaced the battery a couple of years ago, so that shouldn't be it, but you never know...also, I haven't been driving the car much lately, could that be a factor as well (although, the charging voltage is still low after driving the car for well over 30 minutes).

Aug 2, 2006 | 07:30 PM

c4cruiser

Team Owner

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From: Lacey WA RVN 68-69

NCM Sinkhole Donor

My 02 shows around 14.1 to 14.3 right after starting and works down to 13.8 to 13.9 within a few minutes.

I would suspect a bad battery. It could have a dead cell that is keeping the alternator from providing sufficient current to keep the battery charged. Have a reputable shop do a load test on the battery. I'm betting it will fail the test. Badly.

Aug 2, 2006 | 07:33 PM

racetchr

Pro

Joined: Oct 2000

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From: Charlotte NC

Should be in the 13.0 - 14.5 range. My guess would be the alternator. This is the symptoms mine gave when the alt when out.

Aug 2, 2006 | 07:43 PM

BobbyG

Melting Slicks

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From: Rehoboth MA . . . NRA Life Member

St. Jude Donor '06-'07

14.3 volts in my Z06, I'm good to go!

Aug 2, 2006 | 07:44 PM

HIGHRPM

Melting Slicks

Joined: Dec 2000

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Quote:

Originally Posted by raztek

Check your battery voltage before startup..... should be about 12.5v when fully charged.... if its low in voltage (11.5v -12.0v) its either ready to go or your alternator is not charging properly. When voltage drops under 11.0v generally the car won't start.

Aug 2, 2006 | 07:49 PM

fej

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From: Bay Area CA

Mine runs 14.0 to 14.2 during general driving during the day, and with the headlights and PIAA's on usually about 13.8. If I run the AC on high it uses about .5 volts. If it is on low it uses about .1 or .2. Now if I crank the stereo up with the headlights on and play something with bass I can make the DIC drop to 12.2

Sometimes it is enough to make the active handling go nuts. I have to get a cap and do my big three upgrade but that is for another thread.

G'luck
Fej