Alternator at 12.6 volts unless lights are on.
 

I have a 2012 Honda Civic EX. I put in a new battery, but my battery tester always says it needs to be charged. I checked the voltage across the battery with the car at idle and no accessories on and it reads 12.6 volts. If I rev it up it still reads 12.6 volts. With the heater blower running, it reads 12.6 volts at high and low rpms. However, when I turn on the lights, the alternator puts out 14.2 volts at high and low speeds.

Is there a regulator in this circuit that I don't know about? Or is this normal?

Thanks in advance

Dave M.

Re: Alternator at 12.6 volts unless lights are on.
 

FIRST and foremost, Hondas charging systems don't act like what you would see most other cars.
The ELD controlled and battery monitor controlled charging systems are designed to only charge the battery when needed, not all the time. They can and do vary the charging rate and charging voltage depending on the electrical loads in the car, and battery condition.


Is there a real problem with your car?

If you replaced an original battery because it was bad, that's probably normal....be glad you got 5 years out of it. Mine lasted 3 years and 3 months.




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If your car is killing batteries repeatedly (assuming nothing was left on to drain it, and short trip driving habits etc. aren't contributing to a shortened battery llife),

There may be a software update available from your Honda dealership to address a charging system issue, but it did not apply to all 2012 Civics.

Found this link, see if your VIN is within any of the specified ranges:

http://9thcivic.com/forum/threads/vehicle-will-not-start-due-to-a-low-state-of-charge.6732/

Re: Alternator at 12.6 volts unless lights are on.
 

OK, it sounds like it's working normally. I actually replaced the battery last year. The only issue that I have then is that my battery tester always shows the state of charge to be low. I use a Solar BA-5 tester. Every other car in the family tests ok with that tester, so I suspect it's working. Is this just a feature of the car that I should learn to accept?

Dave M.

Re: Alternator at 12.6 volts unless lights are on.
 

Drive in to any Honda dealership service department and ask them for their free battery test (I assume it's a freebie just about everywhere), and get the printout from their machine.

How many of those are 2012 Civics?


As said in the previous reply: There may be a software update available from your Honda dealership to address a charging system issue, but it did not apply to all 2012 Civics.

Follow this link, see if your VIN is within any of the specified ranges:

http://9thcivic.com/forum/threads/vehicle-will-not-start-due-to-a-low-state-of-charge.6732/