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Discussion Starter · #1 ·
Do owners notice low battery voltage (low state of charge) when connected to trailers after long drives? The factory alternator settings use some "smart" charging algorithms that limit output voltage to battery in certain conditions. Looking to gauge if this is a common trait on this platform. Even unloaded, the charging system does not behave in a consistent manner and sometimes battery state of charge is lower than expected. Please share any experiences you have noted during ownership.
 

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2018 SLT+ Crewcab Ecodiesel
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I never have noticed this when towing my trailers. Make sure the trailer connector is really clean (surgically) as this has affected my lights and electric brakes....it may also screw up the draw on the alternator.
 

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I never have noticed this when towing my trailers. Make sure the trailer connector is really clean (surgically) as this has affected my lights and electric brakes....it may also screw up the draw on the alternator.
Hi: Rye&coke... I get a charge out of this. The only message I ever get is "Trailer disconnected", yet when I squeeze the brake controller the trailer brakes come on... hard.
Dieseldragon North shore of Lake Erie.
 

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2016 SLT 4x4 Quadcab 3.53 with a cap
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No, in almost 6 years I have always seen the battery voltage on the dash sitting right on the middle of the gauge, regardless of travel trailer, boat or cargo trailer. The only thing that's still wonky are the flickering dash lights when the running lights and headlights are on and I can live without going to the dealer for that.
 

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2019 RAM 1500 Classic Tradesman 4X2 EcoDiesel
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Almost from the beginning with the new truck, I have been getting "Battery requires attention" messages frequently when starting or shutting off the engine. I took it in for that and other random error messages, and they didn't find any problems with the battery or charging system. I drove about a mile and stopped at the bank--got the message. I now get the message everytime I turn it on or off. On the dash, battery voltage reads 12.9-13 climbing or accelerating, as high as 14.4 going downhill or coasting! Why would voltage drop based on engine load? I know I'll have to take it in again, but I don't have a lot of faith that they can find the problem if they didn't find it this time. I'm skeptical that the workers who moved the truck didn't get the message. I've never had a problem starting it. At least, the other error messages haven't come back.

PS I haven't towed with it yet. I believe the voltage showed about 12 last time I shut the engine off. I assume the value shown while running is actually the alternator input rather than the battery's own voltage?
 

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Discussion Starter · #8 ·
Almost from the beginning with the new truck, I have been getting "Battery requires attention" messages frequently when starting or shutting off the engine. I took it in for that and other random error messages, and they didn't find any problems with the battery or charging system. I drove about a mile and stopped at the bank--got the message. I now get the message everytime I turn it on or off. On the dash, battery voltage reads 12.9-13 climbing or accelerating, as high as 14.4 going downhill or coasting! Why would voltage drop based on engine load? I know I'll have to take it in again, but I don't have a lot of faith that they can find the problem if they didn't find it this time. I'm skeptical that the workers who moved the truck didn't get the message. I've never had a problem starting it. At least, the other error messages haven't come back.

PS I haven't towed with it yet. I believe the voltage showed about 12 last time I shut the engine off. I assume the value shown while running is actually the alternator input rather than the battery's own voltage?
This is what others have noticed. It can be problematic when towing a camper, sometimes engine is only charging at 12-13 volts it will actually pull voltage from the camper batteries. Drive all day to get to the destination only to find the camper batteries need charging now, they were topped off when we left. One normally expects the trailer to charge while driving, not discharge.
 

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Discussion Starter · #9 ·
I never have noticed this when towing my trailers. Make sure the trailer connector is really clean (surgically) as this has affected my lights and electric brakes....it may also screw up the draw on the alternator.
This question/issue only pertains to 2020+ model year ecodiesels. The charging software/calibration was not an issue on Gen2.
 

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This question/issue only pertains to 2020+ model year ecodiesels. The charging software/calibration was not an issue on Gen2.
Yes, my apologies for replying to your thread when it doesn't pertain to my truck. I think it's the way the forum is designed, with the "Recommended for you" window opening which includes all generations and their child forums.
I'll have to pay closer attention to that in the future.
My Bad....
 

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I have a 2022 Laramie. I don’t tow with it, but I have gotten the Charging System Requires Attention message a couple times recently.

I have a boot dryer that I leave plugged into the 12v outlet overnight when my boots are in the truck. Works great. All summer long I didn’t have any issues with it. However, winter has come to Chicago and it was recently pretty cold. I suspect it didn’t like having the draw all night from it. So I purchased a battery tender to mount permanently and connect with the block heater. Hopefully problem solved.

Interestingly, it didn’t give me the message at startup, or the first shutdown after driving to work (1.5 hours, ~80 miles). I got the message when I started again to drive across the job site without having had the boot dryer plugged in.
 

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I haven't had any error messages so far with my '21 Bighorn either towing or unloaded. But having the travel trailer batteries discharge while driving would certainly be a problem as we often travel 5 to 8 hours to campgrounds; when we transition to lithiums in the trailer that may cause other issues. Hopefully my truck doesn't experience the error messages.

@GDE is there a particular trim level in which this problem tends to show up? Or is it scattered across all trims?

Bob
 

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Discussion Starter · #13 ·
I haven't had any error messages so far with my '21 Bighorn either towing or unloaded. But having the travel trailer batteries discharge while driving would certainly be a problem as we often travel 5 to 8 hours to campgrounds; when we transition to lithiums in the trailer that may cause other issues. Hopefully my truck doesn't experience the error messages.

@GDE is there a particular trim level in which this problem tends to show up? Or is it scattered across all trims?

Bob
The battery logic works the same on all trim levels. Do you have a tool to measure battery state of charge? The factory software can cut off all charging at times, we put a charging floor of 13 volts with a ceiling around 15 volts at max output in the GDE tune to prevent undercharging situations.
 

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2021 Ram 2500 Tradesman Crew Cab 6.7 L Turbo Cummins 3.73
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I've towed with the 2017 Ecodiesel all over the place with our RV, I've never had any notice.

And the house batteries would recharge while towing.

RV wiring is a bitch to sort out, but I would start with your house charger/panel and check to see that all the lugs are tight, ground wires too.
 

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I've towed with the 2017 Ecodiesel all over the place with our RV, I've never had any notice.

And the house batteries would recharge while towing.

RV wiring is a bitch to sort out, but I would start with your house charger/panel and check to see that all the lugs are tight, ground wires too.
They're talking about 3rd Gen, this isn't a 2nd Gen issue.

This is the 3rd Gen sub-forum.
 
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I drove my 2020 EcoDiesel today. The only time I saw 14V was when the truck wasn't under load, i.e., turning off the cruise and coasting or when going down a hill. Here's a picture documenting the highest voltage reading.



 
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The system had similar charging characteristics regardless of running empty or towing. 13.0v was the lowest charging number that I saw. In this photo, I'm towing in 7th gear cruising along at 1,900 RPM. For the most part, the charging system stayed between 13.0v and 13.2v the vast majority of the time.

 

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2019 RAM 1500 Classic Tradesman 4X2 EcoDiesel
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The system had similar charging characteristics regardless of running empty or towing. 13.0v was the lowest charging number that I saw. In this photo, I'm towing in 7th gear cruising along at 1,900 RPM. For the most part, the charging system stayed between 13.0v and 13.2v the vast majority of the time. I do like the MPG after a round trip to the mountains, although I don't expect that to stand up to calculations.
Mine has run between 12.9 and 14.4--not quite the 14.9 in your photo. It reads 11.9V before starting after it sat for three days. What does yours read before starting? I do like the EVIC MPG after a round trip to the mountains, although HC will likely be significantly lower. Because the last leg was downhill, calculated range is another 501 miles--almost 800 miles total!

Land vehicle Vehicle Car Motor vehicle Gauge
 

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This is strange, but this is what my build sheet shows. If correct, the 2020 has a bigger alternator.

2015 Ram EcoDiesel
230 Amp Alternator
800 Amp Maintenance Free Battery

2020 Ram EcoDiesel
250 Amp Alternator
800 Amp Maintenance Free Battery
 
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So I put my battery on the charger over the weekend. I bought this Noco direct mount charger NOCO GENIUS2D with the intention of hooking it with my block heater cord so I can plug it in over night. I left it plugged it most of the day Saturday and Sunday. When I came out to my truck this morning the Noco indicated the battery was fully charged. I started up the truck and drove to work. About 50 miles. Little over an hour in the truck. Voltage was above 13 the entire time according to the EVIC, and approached 14.5 a good amount of time as well.

After I parked and got in to work I got the alert from RAM connect again about the charging system failure. When I returned to my truck the EVIC showed 12.2v on the battery.

I’m fairly certain my issue is the battery not holding a charge. I’m going to have to make an appointment and let RAM deal with it. Though they’re all a week out for appointments.

22 Laramie. 26k miles. Have only had the truck since June.

EDIT: When I got home and parked the truck the EVIC indicated 12.6v. After about an hour I looked and the EVIC indicated 12.4v. I’m not going to plug it in tonight, and we’ll see what it looks like in the morning.
 
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