When to replace the underhood battery when you have the etorque system?

[3 Ram Jake]

My underhood 12 volt battery usually hovers around 12.0 volts or a little less when measured by my accurate voltmeter. That is more than 50% discharged. Theoretically should not be able to easily start my truck with the 5.7 engine. But it does. I understand the lithium battery takes over starting the engine? If so, how do you know when it's time to replace your underhood battery??

 

[John Schmidt]

Hi 3 Ram Jake. Can you please clarify the part about your 12 volt battery hovering around 12 volts - and that being 50% discharged?? A 12 volt battery should start the truck - normally when it's at 12 volts. Thanks.

 

[mikeru]

My underhood 12 volt battery usually hovers around 12 volts or a little less when measured by my accurate voltmeter. That is more than 50% discharged. Theoretically should not be able to easily start my truck with the 5.7 engine. But it does. I understand the lithium battery takes over starting the engine? If so, how do you know when it's time to replace your underhood battery??

The 48v battery (lithium battery) powers the etorque starter generator only for stop/start operation. The 12v battery and starter are used for all starts using the fob and push button. Why do you think your 12v battery is 50% discharged when you measure 12v (engine stopped)?

 

[3 Ram Jake]

A fully charged 12 volt battery should read 12.7+ volts on a voltmeter. At 12.0 volts it is at 50% discharge. Just the way 12v batteries have always worked. My older Ram V8 trucks struggle to start on 12.0 level of battery charge.

 

[Wild one]

Hi 3 Ram Jake. Can you please clarify the part about your 12 volt battery hovering around 12 volts - and that being 50% discharged?? A 12 volt battery should start the truck - normally when it's at 12 volts. Thanks.

There's 6 cells in the average automotive battery John and each cell should put out between 2.1 and 2.2 volts each when fully charged.At 12 volts the battery is down to a little under a 50% charge

 

[DanAR]

I would use a load tester to see how it performs when starting the truck and test the cells specific gravity to identify if it’s developed a weak cell. I checked the battery in my barely 1 year old RAM the other day and it only measured 12.5 volts resting and a load test was borderline. I’m not very impressed by the OEM battery .

 

[3 Ram Jake]

The load test will be next, thank you. It's a sealed battery so I can't test electrolyte. My 2024 was manufactured August of 23, and I bought it in January of 24 so it pretty much sat around for 5 months and may have drawn the battery down low enough at some point that it weakened it. Thanks for your input.

 

[John Schmidt]

A fully charged 12 volt battery should read 12.7+ volts on a voltmeter. At 12.0 volts it is at 50% discharge. Just the way 12v batteries have always worked. My older Ram V8 trucks struggle to start on 12.0 level of battery charge.

Outstanding!! Never really looked into that ... I thought a 12v battery reading 12v would be a good thing!! Thanks for the explanation and charts!

 

[Marusho]

I have a '19 with eTorque. My factory battery was bad within 6 months. HOWEVER, the gauge on the dash seems to be programmed to always display 12V, no matter how low the battery is. I went to the dealership of course and they "tested" it, telling me to get lost. After several more failed starts necessitating jump starts, I bought the Walmart EverStart as recommended by Project Farm (Youtube) and I've been happy with it for years. You would think the lithium battery could be used in an emergency, but you'd be wrong. It's very bad engineering that every start of a driving cycle except for the first one is done with the lithium battery, but there is no provision for an emergency start. As a computer programmer, I can almost see the little bit of code that would have been required to effect this fix. Get a battery tester for $20 (not the style from the 1940s with a 50 amp coil that heats up).

 

[Dan Topp]

With my older cars when the battery reaches the 4 yr mark I usually just save time with a digital lighter plug splitter that I can see from outside the car and signals battery tender+ time.

 

[mikeru]

Thanks for the info guys. A volt meter doesn't tell you much. I just use a battery tester which tells me if the battery is bad...

https://www.amazon.com/TOPDON-BT100-Automotive-Alternator-Motorcycle/dp/B07Z67MMGC?&_encoding=UTF8&tag=vs-ag-comm-tester-20&linkCode=ur2&linkId=5a1bc03a53e7f7d449dcae47329dbb1d&camp=1789&creative=9325

 

[Kickboxer]

Don't worry about it until it won't start. Those that bought the
E-Torque should have known they bought trouble, with a capital T.

Lots of complication for no gain, but trouble down the road.

 

[HEMIMANN]

With my older cars when the battery reaches the 4 yr mark I usually just save time with a digital lighter plug splitter that I can see from outside the car and signals battery tender+ time.

Yup. Mfg brochures say 3-5 yrs for flooded. Wide range cause they can't know where they're used, how they're used, and if they're abused!

I generally change flooded @ 4 yrs, regardless of load test results. You're generally on borrowed time by then, even if you've been nice to your battery, keeping it charged, not in a hot climate, etc. Because nobody wants to be dead in the water away from home. Yeah, yeah, there are start devices, but it may not get you home.

AGM's are odd beasts, I'm experimenting with them. Originally for long running trolling motors on boats, they're everywhere now. Their charge profiles are quite different than flooded. Many powersports machines use them now. Snowmobiles and motorcycles for sure.

 

[RamDiver]

A toaster-style battery load tester is often the only reliable method to identify a flakey cell. For $20 at HarbourFreight, why not own 1 or 2 units?

My oldest tester is from the early 80s, not the 1940s and, it still works great.

.

 

[blackbetty14]

I have a 24 with Etorque. If you underhood 12v battery is at 12.0v then the battery is shot. Your 12v battery has a 1yr warranty according to Ram. My 2018 went bad in under 3 years and I did drain it once due to a dash cam being left on and I was able to bring it back but I know thats what killed it. You can get battery chargers that have repair modes to help bring them back but more than likely like my 18 your just buying time/extending the inevitable as the damage is done already. If your vehicle is sitting for more than 2 weeks put it on a tender no if and or buts. These trucks have a ton of electronics on all the time that kill them. When I brought mine back it was less than 1 yr old but it seemed fine, within a year I could feel the cold starts not sounding as peppy and then it died within a year and half out of no where. I luckily had a lithium jump pack in the truck. Take it to ram see if they will replace it if its less than 1 yr. If they give you a hard time get a aftermarket 3-4 yr warranty AGM or similar and don't worry about it. I've been running LifePo4's in my fun cars for years but these new cars are very sensitive to battery voltage which LifePo4 have 13.1v sitting and crank ALOT faster.

 

[clay282]

.

 

[2019_RPX_LTD]

2019 1500 Limited with E-torque. 103K miles. Zero issues from E-torque. Original batteries.

 

[JimmyC]

Don't worry about it until it won't start. Those that bought the
E-Torque should have known they bought trouble, with a capital T.

Lots of complication for no gain, but trouble down the road.

Just another point of view. Bought a 2020 with E-torque in 2019. Drove it 70,000+ miles and 5 years and never had a problem. Still had the original battery, and brakes, when I traded it on a 2024 about a month ago. Loved the 2020. Hope the 2024 is as good.
Have to agree though that I didn’t see much added benefit.

 

[Hardracer]

2019 1500 Limited with E-torque. 103K miles. Zero issues from E-torque. Original batteries.

You just jinxed yourself now....lol

 

[Dusty]

If the original poster measured 12 VDC with a digital meter and the vehicle still starts, I'd compare a reading with another meter of known accuracy.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 123445 miles.