Weird Charging voltage on Zx2

[DrDusty86]

My car has a 1year old cheap Autozone battery.. It is the cheapest Economax battery I could buy. I had put a new alternator on the car the same day about 30k miles ago. After I replaced the alternator I got a ride to the zone and got a fresh battery. Lately I have noticed decreased blower motor speed coming up to a light ideling as well as dash lights dimming very slightly. I pulled out the volt meter and the readings were:
Idling @ 700rpm Every electrical item off 13.81volts
Reving up 13.95volts
Every electrical drawing device on in the car AC/Lights/radio/ interior light Idling @700rpm 13.95volts
Reving up 13.97volts

I put it on a charger at work and it INSTANTLY sent into float mode

Could it be the battery? Should I exchange for the biggest Duralast GOLD AZ has that will fit my car?
Dusty

 

[The_Jeff]

Quasi-normal. Blower fan pitch (speed) is something the ear is very sensitive to.

When the battery goes from charge/float to discharge there's a chemical "black hole" of nearly a volt.

This is why cop cars have heavy duty batteries; they sit idling with highbeams on and the gumball machines going, quietly and slowly discharging their huge battery.

 

[HerrStig]

Originally Posted By: DrDusty86
My car has a 1year old cheap Autozone battery.. It is the cheapest Economax battery I could buy. I had put a new alternator on the car the same day about 30k miles ago. After I replaced the alternator I got a ride to the zone and got a fresh battery. Lately I have noticed decreased blower motor speed coming up to a light ideling as well as dash lights dimming very slightly. I pulled out the volt meter and the readings were:
Idling @ 700rpm Every electrical item off 13.81volts
Reving up 13.95volts
Every electrical drawing device on in the car AC/Lights/radio/ interior light Idling @700rpm 13.95volts
Reving up 13.97volts

I put it on a charger at work and it INSTANTLY sent into float mode Seriously, what do you think the voltaage should be under that load? !4.2 is the generally accepted upper limit.

Could it be the battery? Should I exchange for the biggest Duralast GOLD AZ has that will fit my car?
Dusty

 

[DrDusty86]

So should I put a Huge DuraLast GOLD on the car?

 

[The_Jeff]

I think you're just more in tune with your car and its engineering compromises/ limitations.

 

[DrDusty86]

Driving down the road, everything works perfect.. the AC will blow 42* out of the vents on a 95*+ day, fan is consistent, lights fine. and it is relatively quiet inside the car taking into account it has frameless door windows.

 

[fsskier]

All is working well, leave it alone!

If you were up north the charge voltage would likely be closer to 14.4 volts after a cold start....around 0 f, then would decrease to the voltage you are seeing as underhood temperatures rise.

A higher charge voltage is desirable at very low temperatures, about 13.9 volts would be the "Texas Standard" after warmup.

On most cars now, the voltage regulator is in the alternator, and it is temperature compensated to achieve the above results.

 

[zzyzzx]

Originally Posted By: fsskier
All is working well, leave it alone!


I agree.