Voltage

[M3gen]

hi members, I've browse the forms for several years, but now is the first time I need some help with my 2015 3.8 gen. I've searched the form and found answers for what I was expecting, but did not find the specific answer for a 2015 3.8 sadan. Can same one check the battery voltage ( from the trunk) car running and confirm the voltage is in the 14's. When my car is running voltage is reading high 16v . The dealer is saying the voltage is fine. But I feel it's part of the issues I'm having.

Thanks for your help

 

[pmckechnie]

I will check mine later today but I can tell you that 16V at the battery or anywhere in the car is TOO high. It will COOK the battery, damage electronics, etc.
How did you measure the voltage? Did someone else measure it? Did you do it yourself? If so, is your meter accurate?
If you know the reading was correct and it is running 16V or more, I would find another dealer that has a real tech.

 

[EdP]

I will check mine later today but I can tell you that 16V at the battery or anywhere in the car is TOO high. It will COOK the battery, damage electronics, etc.

It has been a long time since I checked a battery so I figured I'd refresh my memory thinking 14.4 is about right. This is what I found in numerous sources"
12V batteries. Your reading should be anything between 10V and 12.9V. An ideal reading is between 12.4V and 12.7V. Some experts say a reading above 12.6V is better. As soon as your engine is switched on it should increase to 13.7—14.7V.

 

[M3gen]

Thanks for the replys, i did check my self and its does read 16-17 volts with car on. And 12.3 with car off. So this morning when i left for and arrived at work 1 hour later the voltage was good 14.3 car running (cooler weather). I'll see tonight on the way home if heat is a factor... I hate random electrical problems that only show themselves after 40 min of driving.
Im thinking of buying and installing a new alternator even though its still under warranty. Might be cheaper in the long run to replace it myself and prevent premature electronic failure than multiple trips to the dealer and computer failing at 3 years down the road because of excessive heat from the 16 volts

has anyone ever heard of a battery going bad causing voltage Spikes? I have not and can't visually see how it would happen. But am also not an electrician.

 

[EdP]

Im thinking of buying and installing a new alternator even though its still under warranty. Might be cheaper in the long run to replace it myself and prevent premature electronic failure than multiple trips to the dealer and computer failing at 3 years down the road because of excessive heat from the 16 volts
.

Couple of thoughts. First, I have no idea of 17 volts will do any damage so will leave that to the electronics guys.

If it is a problem and under warranty, the dealer should replace or repair it

Alternators have a bunch of diodes and voltage regulating stuff built into them. Before buying either a new or rebuilt unit, are there any alternator/starter shops near you? If so, talk to them and see what they have to say. It may be a cheap and fast repair on yours. There are some YouTube videos on replacing the voltage regulator. Seems more cost effective.

 

[1FstYota]

There is a voltage operating range for most things on a car but 16 is on upper end of what most car stuff will take, and if you have warranty why spend your own money just take it in.

 

[pmckechnie]

M3gen

First, a voltage above 15 V will damage the battery. I am not up on the AGM batterys, but overcharging at a high (15 to 17 V) can cause the older battery to actually explode.
I have seen it many times. It can cause a lot of other problems. 12.5 to 12.7 not running and 13.8 to 14.7 running is OK. Your voltage of 12.3V with engine off is an indication the battery is going
bad. Not enough to notice but damaged some. It will need to be replaced in the near future even if the alternator is replaced.
You need to take a picture of your meter when the voltage is above 15 V and show it to the dealer. It needs to be taken care of NOW. As you indicated about having problems later is very possible.
And yes, a bad battery can cause voltage spikes. But these spikes are very short. A battery won't cause the voltage to go high for more than 1 second. Longer than that can only be caused by the alternator/regulator.

Good luck.

 

[GreatOne]

2017 genesis g80 with engine OFF, I get a steady 11V reading...is this a sign to replace?

 

[GreatOne]

2017 genesis g80 with engine OFF, I get a steady 11V reading...is this a sign to replace?

 

[EdP]

2017 genesis g80 with engine OFF, I get a steady 11V reading...is this a sign to replace?

Yes. Should be 12.6, IIRC. How old is it?
To clarify, just replace the battery, not the car.

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[GreatOne]

Ofc the battery smart ass lol the car is the original that came with the car - never replaced before