Normal voltage?

[jalake]

Hey I'm just looking for a bit of help as searching has provided a large variety of answers

I have a 2021 bighorn Etorque and I'm traveling in Yellowstone and Grand Teton from the east coast.

I noticed my voltage lower than normal then ended up having to jump start the truck about 5 times. Each time I jump started my voltage hovered around 13.4-14.1

I went to the dealer today and they said my battery voltage was ok but amps were way down so they replaced it. No more issues with starting (for now) but my voltage climbs to 13.8 during start up then quickly drops to 12.8

I called my dealership on the east coast as well as the one in Wyoming I visited today they both said it's normal to idle and drive showing 12.8 voltage as the generator will only charge when needed. Is this normal? I've read it should be in the 13-14 range.

 

[Richard320]

For eTorque, yes. Voltage on the 12v system is wacky. There are numerous threads about it.

 

[jalake]

For eTorque, yes. Voltage on the 12v system is wacky. There are numerous threads about it.

I did read a bunch of posts but they say 13-14 idle or driving. I'm just concerned about getting stuck in the mountains 2k miles from home

 

[HSKR R/T]

I did read a bunch of posts but they say 13-14 idle or driving. I'm just concerned about getting stuck in the mountains 2k miles from home

Invest in a good jump starting pack to keep in truck. The one I have off Amazon was under $100 and will jump 3-4 vehicles without needing re-charged, and it charges via USB, so can recharge while driving.

 

[jalake]

Found a dealer in South Dakota where I currently am, they agree it's a failing MGU and they have seen multiple already. They said voltage should be stable around 14v

They said the 12.7-12.9 I am seeing is just a trickle current passing through and keeping everything running. If it totally fails I won't even be able to jump it as the failing MGU damages the batteries as well.

 

[jalake]

Well had the MGU replaced today, voltage still staying around 12.8 dealer now says that to 13v is normal.

Any input anyone? I've attached a video of what it does as well

Still stuck in South Dakota

 

[vtcats]

My experience with 2024 5.7 etourque. Was built 12/23, I purchased 2/24.
When Immediately starting the engine voltage will show 12.2-12.5, depending upon how long it’s sat. It then jumps up to 13.7-13.9v. If I’m driving around for more than an hour or so, it will settle back to about 12.8-13v.
So it seems “normal “ based upon my experience, albeit limited.

 

[kapinallinen2]

A flooded lead acid car battery level of charge is 100% if the voltage is 12.6 VDC or above at rest.
If the battery is not fully charged, then the charging circuit will ramp up the voltage up to 14 volts or so,
backing off as the battery reaches proper level of charge.

 

[jalake]

A flooded lead acid car battery level of charge is 100% if the voltage is 12.6 VDC or above at rest.
If the battery is not fully charged, then the charging circuit will ramp up the voltage up to 14 volts or so,
backing off as the battery reaches proper level of charge.

The weird thing is that it will be up 13-14v on few drives then another time it will only stay in the 12 range. I've been told it will cut charging once battery is full but that doesn't account for all the accessories running as well as.

On a 10 hour drive the voltage will never ramp up, it only slowly falls until I stop and re start the engine. I would expect it to turn on and off charging over that time period of drive if that is truly how the system works.

That's the issue, no one seems to actually know, 2 dealerships told me 12.6 is normal 2 others said I have a failing MGU, which was just replaced with what seems to be no change

 

[kapinallinen2]

I am not an expert by any means, so take this for what it is worth.
To me, it looks like you have a healthy battery that is only taking the charge that it needs.
Running the accessories have nothing to do with the battery voltage, unless the engine is off.

 

[jalake]

I am not an expert by any means, so take this for what it is worth.
To me, it looks like you have a healthy battery that is only taking the charge that it needs.
Running the accessories have nothing to do with the battery voltage, unless the engine is off.

That would be great news, I'm working on speaking directly to a star technician or engineer so hopefully I can get a solid answer for the forums and report back

 

[jalake]

Well put another 600 miles on today, started at 13.1v ended with 12.5 all while driving 70mph.

@RamCares, I contacted the phone number, they opened a case 2 days ago. Still no phone call from case manager. I called the phone number for ramcare, the women case manager (not mine) who answered said she's not my case Manager and won't help, proceeded to transfer me to FCA customer care, who told me they have no power to do anything with these issues.

On my drive today I had to choose between running my headlights in the rain, charging my phone I need in case I have to call when I get stuck AGAIN, or run the AC in the 91 degree temps on our drive. Oh don't forget I couldn't have the voltage drop too low or id lose my trailer brakes as well.

Any single item I turn on drops the voltage below 12.6

 

[kapinallinen2]

Well put another 600 miles on today, started at 13.1v ended with 12.5 all while driving 70mph.

@RamCares, I contacted the phone number, they opened a case 2 days ago. Still no phone call from case manager. I called the phone number for ramcare, the women case manager (not mine) who answered said she's not my case Manager and won't help, proceeded to transfer me to FCA customer care, who told me they have no power to do anything with these issues.

On my drive today I had to choose between running my headlights in the rain, charging my phone I need in case I have to call when I get stuck AGAIN, or run the AC in the 91 degree temps on our drive. Oh don't forget I couldn't have the voltage drop too low or id lose my trailer brakes as well.

Any single item I turn on drops the voltage below 12.6

Sounds like your charging system has taken a dump then.

 

[jalake]

Sounds like your charging system has taken a dump then.

I agree... But I'm still trying to figure out what is controlling the voltage to the 12v battery, is it an integral part of the 48v battery?

The MGU was just replaced so I know it's producing power

 

[kapinallinen2]

Just spent half an hour on alldata reading thru on how this all is supposed to work, no clear answer to what controls what as far as I could see.
MGU talks to 48 volt pack, talks to BCM, BCM talks to MGU, IBS, ECU...

 

[jalake]

Just spent half an hour on alldata reading thru on how this all is supposed to work, no clear answer to what controls what as far as I could see.
MGU talks to 48 volt pack, talks to BCM, BCM talks to MGU, IBS, ECU...

I was curious if an IBS malfunction could tell the system charge conditions are not met such as temperature

 

[Foleyjesse26]

I’m dealing with the same issue. Shaft bearing was going on the MGU, replaced it, now it stays right at 12.5 - 12.6 after driving a bit. I feel like the voltage indicator on the cluster would stay about in the middle before the MGU swap. I don’t recall it ever fluctuating nearly as much as it does now.

 

[jalake]

I’m dealing with the same issue. Shaft bearing was going on the MGU, replaced it, now it stays right at 12.5 - 12.6 after driving a bit. I feel like the voltage indicator on the cluster would stay about in the middle before the MGU swap. I don’t recall it ever fluctuating nearly as much as it does now.

It would make sense for the system to bulk charge then float, the issue is that once the voltage drops, any additional accessories you turn on make it drop more and more... But it never recovers to higher voltage unless the truck is turned off for a few minutes and you re start it

 

[jalake]

Well, we finally made it home. Yesterday I was only able to run my headlights, no other accessories, the voltage would drop too low.
Now time to figure out what's going on.

@RamCares it's now been 6 days since being assigned a case manager, and no one has been in contact, as well as calling the ram care phone number I have had ZERO assistance. Loosing faith in the brand.

 

[Oldphart]

With the factory supplied battery, it was usually in the 13.6 - 14.2 area. After I replaced it with an AGM, it's all over the place; it could be 14.2 at idle and 12.8 on the highway. I've got the Etorque. Is there a setting I can change so the system recognizes that an AGM battery is installed? I believe they have different charge rates than the flooded types.