Brand new truck only charging at 13.1v!?

[blackbetty14]

My new 2024 ram 1500 5.7 etorque has less than 100 miles and it’s a week or so old. Today I noticed that the battery voltage seemed low on the dash. To be fair today was the first time I drove the truck after driving it home a week ago so I didn’t notice the battery. I opened the trailer app and verified voltage is at 13.1v and then I double checked with my meter on the battery itself. Initially voltage climbed to 13.58v and then dropped like a rock to 13.1v. I’m calling the dealer tmrw but wanted to see if it’s something dumb as this affects my life to schedule an appointment etc and the dealer is 40min from me. I’ve always seen batteries charge to 14.1-14.6v so this seems really low.

 

[chopperman1]

Is that with the truck running? If so, ya, that's low. I agree 14.1-.6 is normal charging range. With these ECM controlled alternators/regulators it really could be anything!

 

[Dodge 1500 4X4]

Thats a function of eTorque to sometimes show a lower voltage it's something to do with the 48volt battery behind rear driver's seat, others will chime in I think it's normal.

Congrats on the new rig!!!!

 

[blackbetty14]

Is that with the truck running? If so, ya, that's low. I agree 14.1-.6 is normal charging range. With these ECM controlled alternators/regulators it really could be anything!

This is with truck running. I wanted to confirm charging voltage at the battery. It shows the stock gauges are accurate as well.

 

[blackbetty14]

Thats a function of eTorque to sometimes show a lower voltage it's something to do with the 48volt battery behind rear driver's seat, others will chime in I think it's normal.

Congrats on the new rig!!!!

I did some reading and not much on the subject but found similar info as you. It’s fine till it’s not.

 

[blackbetty14]

This morning I set the battery gauge on the cluster and watched it like a hawk on my way into work. 13.5-13.6v most of the way into work. I'm gona keep an eye on it for a while.

Side note incase someone googles and finds this thread... I got some good info for the charging voltage with the etorque. Etorque motors don't have alternators, it is replaced with the MGU or Motor Generator Unit that puts out 48v to the 48v pack on the back wall of the cab. Inside that pack is a DC/DC converter that steps down voltage from 48v to 12v to charge the starter battery under the hood. On cold start the truck uses the 12v battery to crank over and then once started the 48v pack and MGU take over stop/starts. So the 12v battery is only used on initial starts and to run the accessories, the 48v battery adjusts voltage to the 12v to keep it at full which is anything higher than 12.8v (considered charging). With Engine off resting voltage should be 12.4-12.5v ish. Essentially the 48v pack just tops off the 12v as things are run off it as you drive which is why the voltage fluctuates so heavily. The 12v battery has a IBS (battery sensor) that measures current usage, SOC and SOH to determine battery charge/use/life and I assume some fancy algorithms tells the 48v DC/DC converter to output a certain voltage to keep the battery happy.

FWIW the IBS sensor also means that when the 12v is replaced you need to do it correctly so you don't fry the sensor. Also once the battery is replaced you can do a hard reset by unplugging for 4 hours (leaving the battery unhooked) and then it takes 4 or so restarts with 8hrs off time between starts for the sensor to relearn the new battery. Keep in mind this also affects the etorque/stop start during the learn phase. Most of us always go bigger or swap to a AGM when we do a battery swap which increases the capacity and discharge/charge rates of the battery which the system needs to learn. This means after a battery swap its common to see different voltages till the system learns as well as voltages change as the battery ages.

 

[KeithP]

My new 2024 ram 1500 5.7 etorque has less than 100 miles and it’s a week or so old. Today I noticed that the battery voltage seemed low on the dash. To be fair today was the first time I drove the truck after driving it home a week ago so I didn’t notice the battery. I opened the trailer app and verified voltage is at 13.1v and then I double checked with my meter on the battery itself. Initially voltage climbed to 13.58v and then dropped like a rock to 13.1v. I’m calling the dealer tmrw but wanted to see if it’s something dumb as this affects my life to schedule an appointment etc and the dealer is 40min from me. I’ve always seen batteries charge to 14.1-14.6v so this seems really low.

My 22 Laramie sits right on 13.1v It’s been like that for 25k now so I’m thinking it’s normal.

 

[blackbetty14]

Just wanted to update my charging as been all over the place but recently it has been between 13.9-14.7. I'm not sure maybe its bc I added a wireless light bar switch which causes a slight drain on the battery when it sits. I might need to wire that into a ignition 12v source.