Batteries - Diesel Trucks

[IdaD]

I wanted to solicit a few opinions on batteries. My 2015 Ram is on it's original set of batteries, so about three and a half years of use and a little under 50,000 miles. I haven't had any failures to start yet but I've noticed a couple of times after running the grid heater on cold mornings the last week or two I've had a click before I turn the key back off and then it has fired up on the second try. I assume running the heater immediately prior to starting has run the batteries down enough they are tight on having enough juice for cranking the engine,

Am I at the point I need to replace the batteries? I'm a little on the early end of what I generally consider the replacement cycle for batteries in the other vehicles I've owned. I wondered with two batteries if I'd actually get a little extra life, but on the other hand it is cranking a bigger engine and running the grid heater.

Opinions?

[ktmrfs]

Learjet wrote:

ktmrfs wrote:

philh wrote:

Camreal wrote:
My 2005 discharges the batteries 24 hours a day. I have read that this is normal draw from the electrical systems. If I let the truck sit idle for a couple months I know to put a charger to keep them up. Batteries dont like being discharged.

Thanks to all the computers 🙂

well, I disagree. at least 15 years ago mfg solved the long term accy discharge problem with a several stage shutdown of onboard elecronics.

if they are discharging in less than a few months something is likely amis.

Every vehicle I've had with computers and electronics in it has 3 stages of current draw after shutdown

1) immedidately after turning off ignition with everything off may be in the 1A range
2) exiting and closing doors etc. next stage of shutdown draw goes to the 100-300 ma range
3) after a set time often around 20 minutes full shutdown where current draw is close to battery self discharge rate. takes months to discharge even to 50% SOC

in the full shutdown, things like alarm etc. still are operational but don't wake up until something triggers them.

Now if something is preventing (3) from occuring or there is a fault, and you stay is (2) battery will be discharged way to soon if left unattended.

My truck has Uconnect, which uses a cellular connection to remote start, lock doors and other feature from a phone/computer...your above statement is not correct the cellular radio transmits and receives on a regular basis. Also, passive entry systems use power in standby mode. I think you quoted some old info.

well, my truck a 2015 has similar "features" and a regularly leave it sitting for over a month at a time in the winter and it never has a run down battery. I put it on a battery tender charger (3A) every 4-6 weeks and it on average takes about 3 hours ((9AH) to bring it up to full charge.
Given the batteries are 150AH total, not much drain at all in a month. So at least with mine the "standby" drain is quite low.



In the case of my duramax between shutdown and 48 hours onstar/wifi draw can be as high as 20ma, after 48 hours it wakes up every 10 minutes for a check then shuts down. draw from the remote entry is less than 1ma. after full shutdown.

spec'd max "standby" draw on my truck should be below 30ma after 2 hours.

.030X24=.75AH/day given the truck has 150AH of batteries after 2 months it would be down by 40AH or 75%SOC, easily enough charge to start the truck.

given my experience in trickle charge I'd estimate the standby current is closer to 10 ma.

"After the ignition is turned OFF the control modules will begin to go to sleep (shut OFF). All control modules do not go to sleep at the same time, some may take up to 30 minutes or longer after turning the ignition off before going to sleep. Others such as the ON Star and keyless entry control modules may periodically wake up then go back to sleep."

[Learjet]

ktmrfs wrote:

philh wrote:

Camreal wrote:
My 2005 discharges the batteries 24 hours a day. I have read that this is normal draw from the electrical systems. If I let the truck sit idle for a couple months I know to put a charger to keep them up. Batteries dont like being discharged.

Thanks to all the computers 🙂

well, I disagree. at least 15 years ago mfg solved the long term accy discharge problem with a several stage shutdown of onboard elecronics.

if they are discharging in less than a few months something is likely amis.

Every vehicle I've had with computers and electronics in it has 3 stages of current draw after shutdown

1) immedidately after turning off ignition with everything off may be in the 1A range
2) exiting and closing doors etc. next stage of shutdown draw goes to the 100-300 ma range
3) after a set time often around 20 minutes full shutdown where current draw is close to battery self discharge rate. takes months to discharge even to 50% SOC

in the full shutdown, things like alarm etc. still are operational but don't wake up until something triggers them.

Now if something is preventing (3) from occuring or there is a fault, and you stay is (2) battery will be discharged way to soon if left unattended.

My truck has Uconnect, which uses a cellular connection to remote start, lock doors and other feature from a phone/computer...your above statement is not correct the cellular radio transmits and receives on a regular basis. Also, passive entry systems use power in standby mode. I think you quoted some old info.

[Bedlam]

There are now anti-theft, telemetry and wireless access devices that run constantly even if at low state of draw in addition to radios and clocks. My F250 and 5500 have a minimal amount of these devices, but my Jetta and Sonic have more vampire loads on the battery than for which I care.

[ktmrfs]

philh wrote:

Camreal wrote:
My 2005 discharges the batteries 24 hours a day. I have read that this is normal draw from the electrical systems. If I let the truck sit idle for a couple months I know to put a charger to keep them up. Batteries dont like being discharged.

Thanks to all the computers 🙂

well, I disagree. at least 15 years ago mfg solved the long term accy discharge problem with a several stage shutdown of onboard elecronics.

if they are discharging in less than a few months something is likely amis.

Every vehicle I've had with computers and electronics in it has 3 stages of current draw after shutdown

1) immedidately after turning off ignition with everything off may be in the 1A range
2) exiting and closing doors etc. next stage of shutdown draw goes to the 100-300 ma range
3) after a set time often around 20 minutes full shutdown where current draw is close to battery self discharge rate. takes months to discharge even to 50% SOC

in the full shutdown, things like alarm etc. still are operational but don't wake up until something triggers them.

Now if something is preventing (3) from occuring or there is a fault, and you stay is (2) battery will be discharged way to soon if left unattended.

[larry_barnhart]

I want to give my thoughts on batteries. My wife has many health issues and a heart that is very weak so if I have any clue of a battery issue new batteries are installed at that time. I figure it is a life or death issue.


chevman

[Cummins12V98]

"Be careful when disconnecting. There is a fuse built into the positive battery cable post connector and mine popped somehow during the change. Those post connectors are a dealer only item."

Same happened to my Son. He did not know it had popped. His touch screen was blank and nothing else was effected. The dealer found it while he was getting recalls done. Fuse was $27 and NO labor charge.

[LIKE2BUILD]

IdaD wrote:
I wanted to solicit a few opinions on batteries. My 2015 Ram is on it's original set of batteries....a couple of times after running the grid heater on cold mornings the last week or two I've had a click before I turn the key back off and then it has fired up on the second try....Am I at the point I need to replace the batteries?

Maybe so. Had to replace batteries in my '14 last year. I had similar odd behavior on cold starts when using the grid heater. After testing the batteries I found one of them had a dead cell so I was essentially working off one battery.

Be careful when disconnecting. There is a fuse built into the positive battery cable post connector and mine popped somehow during the change. Those post connectors are a dealer only item.

KJ

[philh]

Camreal wrote:
My 2005 discharges the batteries 24 hours a day. I have read that this is normal draw from the electrical systems. If I let the truck sit idle for a couple months I know to put a charger to keep them up. Batteries dont like being discharged.

Thanks to all the computers 🙂

[Grit_dog]

FLY 4 FUN wrote:

ScottG wrote:

Larry-D wrote:
2015 3500 CTD with 52k miles no problem with the batteries, so far. Probably just jinxed it.

Mine acted very strange when the batteries were older. When cold, I would get a rythmic discharge cycling on my V meter about 5 times as fast as the grid heaters. You could see the lights dim and brighten very quickly (it was NOT the GH's). It didn't seem to hurt anything but I eventually replaced the batts and the symptom quit immediately.

I also noted this exact same symptom on my 12, but when I read my manual it states that its normal after startup for headlights to dim and voltmeter spikes as truck warms up first minute or two.

Daryll

He said it wasn’t the grid heater, it was more rapid than that.

[cummins2014]

Cummins12V98 wrote:
My Son just replaced his on his 2015 with 88k, we ordered our trucks at the same time mine are fine.

He said there was a bit of corrosion that was not visible before removing terminals.

Those appear to be the non AGM's , standard batteries from Costco , I believe they sell for 143.99 ea. ?? .

Mine in my 2014 Ram are nearly 5 years old now, but appear to be okay, wondering if this winter just may get them. I will go with the Costco Batteries if they offer an AGM, not sure if they do, they don't online .

Any reason why your son did not opt for AGM replacements ?

[Camreal]

My 2005 discharges the batteries 24 hours a day. I have read that this is normal draw from the electrical systems. If I let the truck sit idle for a couple months I know to put a charger to keep them up. Batteries dont like being discharged.

[FLY_4_FUN]

ScottG wrote:

Larry-D wrote:
2015 3500 CTD with 52k miles no problem with the batteries, so far. Probably just jinxed it.

Mine acted very strange when the batteries were older. When cold, I would get a rythmic discharge cycling on my V meter about 5 times as fast as the grid heaters. You could see the lights dim and brighten very quickly (it was NOT the GH's). It didn't seem to hurt anything but I eventually replaced the batts and the symptom quit immediately.

I also noted this exact same symptom on my 12, but when I read my manual it states that its normal after startup for headlights to dim and voltmeter spikes as truck warms up first minute or two.

Daryll

[Cummins12V98]

rhagfo wrote:
The important thing that IdaD stated in his original post was replacing BATTERIES (Plural)! This is one time a diesel cost more in maintenance than a gasser.

True story!

[MinnCamper]

I must be lucky! My 06 Duramax still has original batteries.

[Beaker]

Still have original batteries in mine. Our climate is a little bit warmer than yours!
Also have 2 original tires although they should be replaced.