voltage at 12.1 volts normal?

[thaster 10+ year member]

i have a built in voltage meter in my headunit so i decided to check my voltage. I notice that when i start the car(acura integra hatchback) the voltmeter reads 13.9-14.0 but never goes up above 14 volts. Well after a couple mintues of driving, the voltage drops down to 12.1 to 12.2 volts and it will go back up to 13.9 or so for like a couple of seconds then it drops back to 12.1 to 12.2 volts. is this normal or is there something wrong with my alternator, battery, and/or voltage regulator?

Click to read more...

 

[JLJunkieMX107 10+ year member]

when you first start your car, the alternator has to put out more voltage to get the battery back up to full charge. My car will jump up to 15.9 volts at start up then drop to 13.8 after a few minutes. If it peaks then goes down, not a problem. If it stays in that high voltage for long periods of time, that is a good indication your alt is about to crap out

 

[thaster 10+ year member]

so its fine that the voltmeter give a reading of 12.1 to 12.2 volts most of the time im driving?

 

[iceteebone 5,000+ posts]

so its fine that the voltmeter give a reading of 12.1 to 12.2 volts most of the time im driving?

No it's not. A normal car should charge at about 13.5-14.5 volts. Your battery should be at 12.5 volts at rest. Is your voltage dropping while playing your system? Also a headunit isn't the most reliable gauge.

 

[thaster 10+ year member]

my volts goes up to 13.8 to 14.0 from time to time when im driving but most of the time the voltss stay near the lower 12 volts region. imma take my car to autozone to get it tested for free.

 

[05gliguy 10+ year member]

Also a headunit isn't the most reliable gauge.

x2, my HU is .4 - .5 off below actual voltage.

EDIT: Sounds like the alternator to me.

 

[iceteebone 5,000+ posts]

my volts goes up to 13.8 to 14.0 from time to time when im driving but most of the time the voltss stay near the lower 12 volts region. imma take my car to autozone to get it tested for free.

Do you have a dmm? Test your voltage at an idle with the system off. It should stay at a constant 13.5-14.5 volts

 

[thaster 10+ year member]

no i dont have a dmm but i could probably buy one for like 15 bucks at radio shack or something

 

[canadiancav 10+ year member]

^Beat me to it.

 

[05gliguy 10+ year member]

You might want to get one, they are very helpful.

 

[fbi90909 5,000+ posts]

that's normal for honda/acuras.

my voltage is the same on stock alt with additional red top in back with big 3.

starting the car i'll see my voltage go up from 11.6(1 second worth right after crank[batt rest at 12.3 when car is off]) to a 14.3-4 in less than 3 seconds. after my engine warms up to it's normal temp it would drop to 12.1-3

as i drive if i go over 60mph my alt would kick in and stable voltage to 14.3(lights and a/c off or on)

turn on a/c driving under 60mph i get a 12.9, on LOW a/c, max a/c it's about 12.1

headlights on under 60mph is about 13.9-14.1

headlights and a/c on max an average of 12.9

note: that's with the stereo off. with the stereo on my voltage tends to hang out at around 12.1 and drop to 11.7 slowly if i sit at stop lights. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

just drive around for a while and study the voltage while running things. check if there's a certain speed where the alt kicks in or if it's an rpm rate(most likely 2k rpms the alt will kick in).

check and see with the head lights on and off.. or with the a/c.

but when testing give each test about 10 minutes worth of driving.

oh plus those little small batteries that honda/acuras use are shitty in maintaining strong voltage //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[tommyk90 5,000+ posts]

that's normal for honda/acuras.
my voltage is the same on stock alt with additional red top in back with big 3.

starting the car i'll see my voltage go up from 11.6(1 second worth right after crank[batt rest at 12.3 when car is off]) to a 14.3-4 in less than 3 seconds. after my engine warms up to it's normal temp it would drop to 12.1-3

as i drive if i go over 60mph my alt would kick in and stable voltage to 14.3(lights and a/c off or on)

turn on a/c driving under 60mph i get a 12.9, on LOW a/c, max a/c it's about 12.1

headlights on under 60mph is about 13.9-14.1

headlights and a/c on max an average of 12.9

note: that's with the stereo off. with the stereo on my voltage tends to hang out at around 12.1 and drop to 11.7 slowly if i sit at stop lights. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

just drive around for a while and study the voltage while running things. check if there's a certain speed where the alt kicks in or if it's an rpm rate(most likely 2k rpms the alt will kick in).

check and see with the head lights on and off.. or with the a/c.

but when testing give each test about 10 minutes worth of driving.

oh plus those little small batteries that honda/acuras use are shitty in maintaining strong voltage //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

Wrong.

At idle and after the car is warmed up your voltage should still be above 13 volts. 13.5-14.5 like iceetee said.

 

[themommyvan 10+ year member]

I have the same HU and the voltage is around .4 off at all times. I also have a friend with the same HU and his always reads 13 volts. Even with the car off.

But to be on the safe side I would say like the others and get a DMM and make sure.

 

[tommyk90 5,000+ posts]

I have the same HU and the voltage is around .4 off at all times. I also have a friend with the same HU and his always reads 13 volts. Even with the car off.
But to be on the safe side I would say like the others and get a DMM and make sure.

x2

A DMM comes in handy ALL the time. Very good investment.

 

[thaster 10+ year member]

i just went to autozone to get my alternator and battery checked. The worker say everything was fine. I notice that when i turn my headlights on the battery voltage stay at 13.4 or so but without headlights the battery voltage goes down to 12.1.