Dead Battery

[bluecheese]

21 Ram 1500 etorque

My truck sat for 5 days while I was out of town. This evening the battery was completely dead.

I tried jumping it with my wife’s car, but the engine wouldn’t crank

I let her car charge my battery for 10 minutes and the truck finally turned over.

But I now have a Check Engine Light. The voltage is showing as 13 volts. I drove the truck around a little, turned it off and let it sit for 30 minutes.

The truck fired up again, but I still have the CEL. The voltage starts somewhere in the mid 12s, it increases to 13.6, then drops to 13.

The 12v battery was replaced less than 6 months ago.

Any ideas?

 

[Wild one]

21 Ram 1500 etorque

My truck sat for 5 days while I was out of town. This evening the battery was completely dead.

I tried jumping it with my wife’s car, but the engine wouldn’t crank

I let her car charge my battery for 10 minutes and the truck finally turned over.

But I now have a Check Engine Light. The voltage is showing as 13 volts. I drove the truck around a little, turned it off and let it sit for 30 minutes.

The truck fired up again, but I still have the CEL. The voltage starts somewhere in the mid 12s, it increases to 13.6, then drops to 13.

The 12v battery was replaced less than 6 months ago.

Any ideas?

View attachment 584568

Put the battery on a battery charger overnight,and see if anything changes.The truck won't actually charge up a dead battery,it'll only maintain it,you need to use a battery charger to bring the battery back up.

 

[bluecheese]

I just started the truck after sitting overnight. It was a little hesitant, but it started. The voltage was at 13.8 volts at idle. Not sure what that means though.

 

[MeatCurtains]

Put the battery on a battery charger overnight,and see if anything changes.The truck won't actually charge up a dead battery,it'll only maintain it,you need to use a battery charger to bring the battery back up.

The alternator will absolutely charge a dead battery. If it didn't then the battery would die after a few months of starting because it was only "maintaining" it.

It sounds like the battery might be going bad. 5 years is a little young, but not unheard of.

 

[CanuckRam1313]

The alternator will absolutely charge a dead battery. If it didn't then the battery would die after a few months of starting because it was only "maintaining" it.

It sounds like the battery might be going bad. 5 years is a little young, but not unheard of.

Incorrect!

@Wild one IS correct!!

While a vehicle's alternator does charge the battery while you drive, it is not designed to fully recharge a dead battery. Its primary purpose is to maintain a healthy battery's charge and power the car's electronics while the engine is running.

The Limits of Alternator Charging

• Surface Charge Only: Driving for a short period (like 30 minutes) usually only provides a "surface charge." This might be enough to start the car once more, but it doesn't deeply recharge the battery.
• Highway Speeds Required: Alternators produce minimal current at idle (600–800 RPM). You typically need to maintain speeds above 55 MPH or engine speeds over 1,000–1,500 RPM for the alternator to provide enough surplus energy to charge the battery.
• Time Consumption: To truly recharge a deeply discharged battery using only an alternator, you would need to drive for 4 to 8 hours at highway speeds.

Risks of Using an Alternator for a Dead Battery

• Alternator Damage: Forcing an alternator to charge a completely dead battery can cause it to overheat and eventually fail because it is working at maximum capacity for a prolonged period.
• Incomplete Charge: Most alternators will never bring a battery back to 100% capacity; they are "maintainers" rather than dedicated chargers.

Recommended Action
If your battery is dead, the most effective and safest method is to use a dedicated External Battery Charger at home or a garage. These devices are designed to safely push current into the battery at the correct rate to restore its health without straining your vehicle's electrical system.

 

[MeatCurtains]

Incorrect!

@Wild one IS correct!!

While a vehicle's alternator does charge the battery while you drive, it is not designed to fully recharge a dead battery. Its primary purpose is to maintain a healthy battery's charge and power the car's electronics while the engine is running.

The Limits of Alternator Charging

• Surface Charge Only: Driving for a short period (like 30 minutes) usually only provides a "surface charge." This might be enough to start the car once more, but it doesn't deeply recharge the battery.
• Highway Speeds Required: Alternators produce minimal current at idle (600–800 RPM). You typically need to maintain speeds above 55 MPH or engine speeds over 1,000–1,500 RPM for the alternator to provide enough surplus energy to charge the battery.
• Time Consumption: To truly recharge a deeply discharged battery using only an alternator, you would need to drive for 4 to 8 hours at highway speeds.

Risks of Using an Alternator for a Dead Battery

• Alternator Damage: Forcing an alternator to charge a completely dead battery can cause it to overheat and eventually fail because it is working at maximum capacity for a prolonged period.
• Incomplete Charge: Most alternators will never bring a battery back to 100% capacity; they are "maintainers" rather than dedicated chargers.

Recommended Action
If your battery is dead, the most effective and safest method is to use a dedicated External Battery Charger at home or a garage. These devices are designed to safely push current into the battery at the correct rate to restore its health without straining your vehicle's electrical system.

The purpose or not.

It absolutely will charge a dead battery. If it couldn't the system wouldn't work. Every single day people leave accessories on, kill a battery, jump, drive home or where they are going and the battery will have a full charge after several days depending. You can test this yourself.

The PURPOSE of the alternator is to provide power to the system and maintain the battery, but it absolutely WILL charge the battery.

 

[CanuckRam1313]

21 Ram 1500 etorque

My truck sat for 5 days while I was out of town. This evening the battery was completely dead.

I tried jumping it with my wife’s car, but the engine wouldn’t crank

I let her car charge my battery for 10 minutes and the truck finally turned over.

But I now have a Check Engine Light. The voltage is showing as 13 volts. I drove the truck around a little, turned it off and let it sit for 30 minutes.

The truck fired up again, but I still have the CEL. The voltage starts somewhere in the mid 12s, it increases to 13.6, then drops to 13.

The 12v battery was replaced less than 6 months ago.

Any ideas?

View attachment 584568

I just went through a battery dilemma last week.

I tried using my NOCO Genius5 charger on my old battery to bring it back to life (about a 3.5 to 4 year old AGM) and while it charged it overnight, the moment I put my 100A battery load tester on it the battery proved to be done!

I bought a new H8 AGM Odyssey battery and put my charger on it overnight to ensure it was at peak charge and installed it. All is good with the world now.

As your truck has eTorque, perhaps there is something else going on with the battery drain issue?

I'd start by getting a decent charger (the NOCO Genius 5 is about $100) and start there.
I'd also get a 100A battery load tester as well (usually under $40).

 

[bluecheese]

Well that didn’t last long. Battery dead again.

 

[Dean2]

So, did you charge it for 10 hours with a quality battery charger and test the battery after charging?

 

[Wild one]

The purpose or not.

It absolutely will charge a dead battery. If it couldn't the system wouldn't work. Every single day people leave accessories on, kill a battery, jump, drive home or where they are going and the battery will have a full charge after several days depending. You can test this yourself.

The PURPOSE of the alternator is to provide power to the system and maintain the battery, but it absolutely WILL charge the battery.

You apparently don't know much about the charging systems on vehicles these days
You're analogy of driving several days and the battery is back to fully charged after being dead is BS,unless that several days of driving included a couple of 200 mile or more trips.
Yes it's been tried by several guys on here
The only way to bring a battery back up after it's been discharged is with a battery charger,especially if you don't want to replace the alternator on a yearly basis.
Vehicles aren't the same as they were 40 years ago

 

[MeatCurtains]

You apparently don't know much about the charging systems on vehicles these days
You're analogy of driving several days and the battery is back to fully charged after being dead is BS,unless that several days of driving included a couple of 200 mile or more trips.
Yes it's been tried by several guys on here

Unless there is some profound difference between the 4th gen and the 5th Gen I am correct. I literally just went through this with mine.

 

[RamDiver]

.

 

[TradesmanGuy]

I have been using my Tradesman quite a lot as a work truck. Lots and lots of starts and stops while I move firewood around and spread gravel around to repair my driveway. Got a CEL, and had the battery charge gauge blinking at me. Charged it with my NOCO Genious 5A and alls good. If this happens again, I'm going to upgrade to an H8 battery. These Rams are too sensitive to battery weakness and I can't even open the door to get something out of the cab without all the lights turn on for a minute. A waste of juice if you ask me.

 

[Wild one]

Unless there is some profound difference between the 4th gen and the 5th Gen I am correct. I literally just went through this with mine.

Load test your battery with an old school toaster style tester,i'll lay odds all you're getting is a surface charge,and not a charge that'll maintain a load and pass a test with the old school battery testers.
Did you read post #5 and more importantly,did you actually comprehend what the post said,as by the way you're arguing,it sounds like the information went right over your head
It's pretty common knowledge these days that the majority of charging systems that are run by the vehicles computor,only "maintain a healthy battery"

 

[bluecheese]

My buddy stopped by earlier with his battery charger. The charger said the battery was at 17%.

Battery has been charging for 7 hours or so and it’s currently at 70%.

I’m hoping this was just a fluke and I have no more issues once it’s charged.

 

[MeatCurtains]

Load test your battery with an old school toaster style tester,i'll lay odds all you're getting is a surface charge,and not a charge that'll maintain a load and pass a test with the old school battery testers.
Did you read post #5 and more importantly,did you actually comprehend what the post said,as by the way you're arguing,it sounds like the information went right over your head
It's pretty common knowledge these days that the majority of charging systems that are run by the vehicles computor,only "maintain a healthy battery"

Funny enough. It did. Must be a miracle.

A surface charge will absolutely be the issue if you check it immediately after shutting the engine down. That dissipates after a bit.

You guys do you. You can't maintain a battery without the ability to charge the battery, period. Thats how maintaining a battery works.

 

[RamDiver]

My buddy stopped by earlier with his battery charger. The charger said the battery was at 17%.

Battery has been charging for 7 hours or so and it’s currently at 70%.

I’m hoping this was just a fluke and I have no more issues once it’s charged.

Do you have any idea of the voltage level when you started charging?

.

 

[bluecheese]

Do you have any idea of the voltage level when you started charging?

.

I’ve never used this charger before, so I may be wrong about what it’s telling me. But when I first connected it to the battery, it said 12 volts.

 

[Wild one]

I’ve never used this charger before, so I may be wrong about what it’s telling me. But when I first connected it to the battery, it said 12 volts.

If all it read was 12 volts,you basically have a dead battery,a good battery should read between 12.6 to 13.2 volts. There's 6 cells in a 12 volt battery and each cell when fully charged should be between 2.1 and 2.2 volts.
I'm to lazy tonight to dig up a battery chart for you,but at 12 volts you're battery is pretty well dead

 

[bluecheese]

I’ll run by Autozone tomorrow morning and have it tested.