driving voltage

nat3d

Wait, I don't drive a civic anymore....
3,335
1,566
Adams MA
Vehicle Model
Ford Focus ST
Body Style
Hatch
hey guys i have a voltmeter and as im driving ive noticed that on ocasion rather than run at 14.3v my car has been running at 12.5v and when it first started it was only when i was on the gas it would drop to that but now it seems constant (as of my drive home) whats going on?
 
I got you @nat3d .

A car alternator needs to be putting out at least 13-14 volts (ideally between 13.8 and 14.2 volts) to effectively charge a 12 volt car battery. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery. On the other hand, if its constantly at 14v than your battery isnt holding its charge or its losing charge somewhere in your system very fast.

As long as its between 13-14 volts, your alternator is working fine. So its just the battery at this point.
 
I got you @nat3d .

A car alternator needs to be putting out at least 13-14 volts (ideally between 13.8 and 14.2 volts) to effectively charge a 12 volt car battery. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery. On the other hand, if its constantly at 14v than your battery isnt holding its charge or its losing charge somewhere in your system very fast.

As long as its between 13-14 volts, your alternator is working fine. So its just the battery at this point.
its been sitting at 12.something though :/
 
i have a volt meter wired
 
The charging system on the newer Civics don't work like they have traditionally - there will be times when you are driving that the alternator will not be charging. The charging protocol has been changed to improve economy.
 
I wouldnt worry about it till there is actually a problem. I could take a vid of how my voltage is when I drive if it would help you any.
 
thanks a lot guys. i think ill just wait it out and keep my jump batt charged and if you want to @ADExternal that would be cool
 
the insider is correct, at least for Si models. Others, I have no idea. Try turning on your headlights. Your voltage should increase. If not, I'd take it to the dealer.
 
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