What charging voltage does your Ram run at

[Springcrik]

After owning a 98.5 2500 with the 5.9, I have a new-to-me 2018 3500 dually with the 180-amp alternator. No issues at all but one thing I would like to understand better. The displayed charging voltage is always “13”. Not 13.2 or 13.6, etc., just 13. I have owned the truck for 3 months and it has never shown the slightest sign of weak batteries,slow cranking, or any check engine/fault codes. My son-in-law has a 2015 3500 and his display always shows 13 as well. I have worked with Cummins diesels for decades (Case farm equipment) and the voltage standard for (Bosch) charging systems was 14.2 volts. Yes, those alternators had thermal compensation and voltage was lower in summer heat and higher in winter cold.

Not to stray too far from my question but there is a recent Gen 4 TDR alternator topic that discusses the possibility of the alternator going to full charge during regenerative braking. I turned on full Turbo braking mode and made a few deceleration tests while monitoring the displayed voltage. It was rock steady at 13…I don’t think 2018s have regeneration.

So please reply and tell me what charging voltage your Gen4 normally displays

 

[lpennock]

13v is the computer giving you a feel good number. Real value is closer to 14.2 and can get over15v in sub freezing temperatures. Bottom line it is fake.

 

[AH64ID]

13V most the time. Sometimes 14V. It usually matches the readout on the CTS2, thou I don’t look at it often.

 

[Topzide]

This is the reason that I'm adding a separate digital readout for voltage. I know not really necessary but I'd like to know a bit closer and a bit of a gadget freak! I know on mine it'll say 14v for about the first 10 minutes of driving then drops back to 13v. Like mentioned, it's what the computer is telling the display what to show. Only be concerned when it shows 12v or lower! Enjoy that new ride!!!!!

 

[CEppinger]

What does the EVIC read when the engine is not running?

 

[AH64ID]

What does the EVIC read when the engine is not running? View attachment 130035

That must be in ACC, not RUN.

On another note, I used to have DPF stat up as well but changed it out. The top light is always green in regen, so it seemed redundant to have DPF stat showed.

 

[lpennock]

I did some testing on it this morning. The display isn't fake, it is a integer display so really only good to tell you are charging or not. It will display 12V for 12.0-12.9V, 13V for 13.0-13.9 (see attached photos) and probably 14 for 14.0-14.9 but I can't check that until the weather cools. (Battery voltage is bottom left on CTS)

 

[AH64ID]

I did some testing on it this morning. The display isn't fake, it is a integer display so really only good to tell you are charging or not. It will display 12V for 12.0-12.9V, 13V for 13.0-13.9 (see attached photos) and probably 14 for 14.0-14.9 but I can't check that until the weather cools. (Battery voltage is bottom left on CTS)

View attachment 130045

View attachment 130046

That matches what I have seen.

What's with the red warning?

 

[Ozymandias]

Intelligent Alternator aka. charging system.
It just charges as much as it needs.
There is a shunt on the battery so the Truck knows exactly how the SOC of the battery's is. Every modern car does it like that to safe fuel, that's absolutely nothing special anymore.

 

[lpennock]

That matches what I have seen.

What's with the red warning?

Second photo was engine off in run position so it was giving a warning for low oil pressure.

 

[AH64ID]

Second photo was engine off in run position so it was giving a warning for low oil pressure.

Interesting. I guess I have alarms off, and don’t bother with the fake gauges anyhow.

 

[lpennock]

Interesting. I guess I have alarms off, and don’t bother with the fake gauges anyhow.

My CTS has a real oil pressure sensor attached. I did turn off the audio alarm for oil pressure as the truck will tell me if I have a sudden drop. Normally when I shut off the truck the upper right gauge would go red but because I shut it off and then turned it right back on the CTS cleared that alarm even though it did keep the red alert. One of those fast shut off/on anomalies.

 

[Springcrik]

I appreciate all of the information, thanks guys.