Battery drain issues

[ejmguru]

Hi everyone! Has anyone had any issues with the 2025 Ram 1500 not starting after sitting a day or two? This is my 2nd 2025 RAM 1500, Bighorn, as the 1st one had to be returned due to the same issue of not starting, only worse. The dealer wasn't able to repair the 1st RAM, so now I have a new one again. Yesterday went out, started the truck and took it through the car wash. After returning, shut off the truck and in an hour tried to start it as we were headed to a Baptism event, and it was dead. This has happened a couple of times. The charging system is always showing 13.8 to 14.4 volts going to the battery, but it seems the battery isn't charging. Not sure if the battery is dead (dealer replaced both batteries on the 1st Bighorn and that didn't solve the issue) or there is a parasitic drain on the battery. Currently I have to carry a battery pack with me to ensure that I can jump the truck to start it. I love the truck and just checking to see what I might be able to do to ensure the truck will start when I need it. Thanks for any information. Also, has anyone permanently installed a battery maintainer in their RAM?

 

[Pikeman_66]

Hi everyone! Has anyone had any issues with the 2025 Ram 1500 not starting after sitting a day or two? This is my 2nd 2025 RAM 1500, Bighorn, as the 1st one had to be returned due to the same issue of not starting, only worse. The dealer wasn't able to repair the 1st RAM, so now I have a new one again. Yesterday went out, started the truck and took it through the car wash. After returning, shut off the truck and in an hour tried to start it as we were headed to a Baptism event, and it was dead. This has happened a couple of times. The charging system is always showing 13.8 to 14.4 volts going to the battery, but it seems the battery isn't charging. Not sure if the battery is dead (dealer replaced both batteries on the 1st Bighorn and that didn't solve the issue) or there is a parasitic drain on the battery. Currently I have to carry a battery pack with me to ensure that I can jump the truck to start it. I love the truck and just checking to see what I might be able to do to ensure the truck will start when I need it. Thanks for any information. Also, has anyone permanently installed a battery maintainer in their RAM?

i wonder if the dealer put some kind of tracking device or something hidden in it that is drawing power. really weird 2 trucks same issue from the same dealer. or the pulsing 3rd brake light module some dealers like to put on and charge you for. just a random thought

 

[ejmguru]

Just replaced the aux battery from the dealer. I had to remove/replace as the truck was completely dead. Once installed, the truck started again, and I was able to take it to the dealer. Just checked after driving home and the aux battery is down to 11.6 volts after about 45 minutes. Something is definitely running after the truck is powered down. Just can't pinpoint the issue.

 

[Pikeman_66]

Just replaced the aux battery from the dealer. I had to remove/replace as the truck was completely dead. Once installed, the truck started again, and I was able to take it to the dealer. Just checked after driving home and the aux battery is down to 11.6 volts after about 45 minutes. Something is definitely running after the truck is powered down. Just can't pinpoint the issue.

yep, you must have something draining it. it's weird that its 2 different trucks from the same dealer though.

 

[ejmguru]

My 2025 RAM has now been in the shop since last Tuesday. The OBD code was the same as the 1st truck, P068A, which the dealer said they fixed on the lemon truck. Haven't heard anything from the dealer since dropping off the truck.

 

[kapinallinen2]

"or there is a parasitic drain on the battery"

Most likely the case.
Easiest way to see if that is causing the dead battery is to connect a keep-alive power supply with adequate amperage, disconnect the main battery and see what is being drawn with the ignition off and doors, hood shut. This was my truck when the modules kept waking up and "polling"

 

[drect]

Most likely the case.
Easiest way to see if that is causing the dead battery is to connect a keep-alive power supply with adequate amperage, disconnect the main battery and see what is being drawn with the ignition off and doors, hood shut. This was my truck when the modules kept waking up and "polling"

did you find out the cause of the drain and the fix?

 

[jlgomez10]

It may just be that I'm the only dummy, but on my 2025 Laramie I left a power plug to my dashcam connected to the dashtop 12v (cigarette-style) port. No device, just loose connectors tucked away. It turns out that the 12v supply is not switched power and is connected directly to the battery. The 12v connector must have had an internal LED or something, because it happily kept drawing power while the truck was off. I had never seen a multi-meter read 4.6v on a 12v battery before.

 

[kapinallinen2]

did you find out the cause of the drain and the fix?

Yes. In my case it was a less than perfect connection at the driver side fender main ground, next to the hood hinge.
I cleaned it really good and applied conductive silver grease to keep it from getting oxidized again, knock on wood, been good since Jan 20 2022.

 

[kapinallinen2]

It may just be that I'm the only dummy, but on my 2025 Laramie I left a power plug to my dashcam connected to the dashtop 12v (cigarette-style) port. No device, just loose connectors tucked away. It turns out that the 12v supply is not switched power and is connected directly to the battery. The 12v connector must have had an internal LED or something, because it happily kept drawing power while the truck was off. I had never seen a multi-meter read 4.6v on a 12v battery before.

A dash-cam does not draw enough juice to kill a healthy battery over night IMO.

 

[jlgomez10]

No, you’re right. In my case I think it took a couple of weeks when we were only doing very short hops driving my wife to PT sessions. The alternator didn’t have much time/distance/speed to recharge the battery.

 

[kapinallinen2]

No, you’re right. In my case I think it took a couple of weeks when we were only doing very short hops driving my wife to PT sessions. The alternator didn’t have much time/distance/speed to recharge the battery.

Short hops could do it no doubt.

 

[Jako]

No, you’re right. In my case I think it took a couple of weeks when we were only doing very short hops driving my wife to PT sessions. The alternator didn’t have much time/distance/speed to recharge the battery.

Yeah, father and father in law's batteries both suffered from that scenario. My take away from my reads a 20 minute highway ride is what is needed for a proper charge. Electrical engineers and mechanics please chime in with your knowledge and experience.

 

[Sunnyflowerchristy]

Just purchased a 2025 ram 1500 big horn and had to have it towed to the dealer for the battery issue

 

[AlaskanDan]

Any resolution to this? I just brought my truck back to the dealership for sounds like the same issue. Initially brought it back because the auto start wasn’t working. Then when the auto shutoff was active at stoplights, the voltage would drop to 11.8-11.9 volts before the light would change. The radio won’t hold date or time, dealership installed a new main battery, but didn’t solve it, back again to test the aux battery, but they found a parasitic voltage drain. They are working with the engineers now and hopefully will find the issue. Wonderful experience buying my first new vehicle.