Alternator Charge Voltage

[2001gw]

Hi Guys...I'd like to chime in here.

I have a 2021 RAM 1500 with about 4,000 miles on it. I have always noticed that while driving the battery voltage is always around 13.7 or 13.8. A couple of days ago I decided to insert a digital voltmeter into the 12v accessory port and drive around (thinking that maybe the truck's meter was reading low). They both read the same thing. (The digital meter is upside down because that's the only way it would fit).

PS: I just went and checked my battery voltage with the engine not running. It is 12.46v

 

[Jnav]

Hi Guys...I'd like to chime in here.

I have a 2021 RAM 1500 with about 4,000 miles on it. I have always noticed that while driving the battery voltage is always around 13.7 or 13.8. A couple of days ago I decided to insert a digital voltmeter into the 12v accessory port and drive around (thinking that maybe the truck's meter was reading low). They both read the same thing. (The digital meter is upside down because that's the only way it would fit).

PS: I just went and checked my battery voltage with the engine not running. It is 12.46v

Do you have Etorque? Our pickups with Etorque are all over the place with voltage while running

 

[2001gw]

Yes...5.7 eTorque

 

[‘19ramlveryeha]

what type(specs)battery did you get

Super start platinum from oreily. Whatever that means.


2019 Ram 1500 ORP “long bed” - setting #5 bilsteins, 2”mopar ucas, hellwig sway bar, tonneau cover, bed mat, 20” Laramie sport wheels on 285/60r20 falkens. Flowmaster outlaw.

 

[‘19ramlveryeha]

I will note after driving around it counted back to like 13.8-14 so seems to be back. Thought it might be the alternator but must have been the battery. Bought the truck in July of ‘19.


2019 Ram 1500 ORP “long bed” - setting #5 bilsteins, 2”mopar ucas, hellwig sway bar, tonneau cover, bed mat, 20” Laramie sport wheels on 285/60r20 falkens. Flowmaster outlaw.

 

[1500Bear]

The charging system voltage will vary with temperature: higher when colder, lower when warmer.

For lead acid batteries the absolute charging voltage limit for recharge should not be above 14.7 volts at 77 F (battery temperature), or 14.1 volts at 104 F. At -20 F, the charging voltage should not be above 15.3 volts.

Automotive systems are regulated to overcharge in the recharging cycle. This is to prevent sulfation. When a lead acid battery is 100% charged, the terminal voltage (no load) should be 12.36 volts or more depending on temperature.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 047848 miles.

My voltage during driving usually holds at 14.6 ok the hwy around 1800-2000 RPM. I just replaced my factory battery with a new one (less than 3 years but more than 36k mile warranty). I'm wondering if the system / alternator is actually over-charging the battery and shortened the life. I previously had a rule of thumb in mind that 13.7-14.3v was normal for alternator voltage. Thoughts?

 

[RamNoLimits]

Hi All- Thanks for all of the information!!
Here are some additional observations I've made in the first few weeks with the new truck.

I have a RAM 1500 Limited 5.7 eTorque with about 1k miles on it now.
I noticed the battery voltage low when I first got the truck, similar to others, and I was a little concerned.
I've been driving with the battery voltage gauge on, and I can say that is really all over the place for me.

Generally, when I start the truck:
it comes on at about 12.4 V and slowly creeps to 13.x.
The voltage can vary all over the place from there, dipping to the 12s and 14s.
I haven't seen an 11.x or a 15.x; I think the limits I've seen are 12.4 and 14.4 or so.
It seems to follow the idea of changing alternator mode based on engine demands (accelerating = lower voltage, decelerating downhill = higher voltage); though it doesn't seem that eTorque trucks work like that, the 48V battery should be charging the 12V battery... but that is beyond me at this point.

Other times, it's like a whole different truck.:
It starts up and shows 14.1V dead center of the gauge, and holds there like it was born to run 14.1V 24/7 like a champion.
This happened a couple of times after I was in the truck w/o the motor and playing with the 12" (there are a lot of settings !! ) So it could be that the truck sensed the 12V battery needed charging and so it charged it, vs other times it was just supplying enough not to discharge

I've asked the sales guys (why would I punish myself like that?), service writers, and techs about this, and none of them had ANY idea at all.
I don't think any of them ever look at the battery gauge.
Maybe it's the car audio / marine experience, but a 12.4V reading with the motor running scares me.

I'll continue to watch it.

Let us know what you see on your truck!