400mi 2020 Silverado RST Duramax DEAD

[BIGDOGx]

16 hours ago, markhunt said:

I have a 2020 GMC 2500HD 6.6 and have had it towed to dealer twice in the past 2 months with totally dead batteries. they could not find any problems. Scary.

Go buy an interstate battery and your problem will likely go away. A shame imo because delco batteries have seriously been a rock solid part of gm trucks for the last few decades for me anyways, my last truck the battery lasted 9 years, my current truck is going on 7 years now. 

 

I have seen many post regarding gm batteries now with the 19 and up models, more than likely they ain't what they use to be unfortunately.

[Colossus]

actually batteries are much better then they used to be.  It's the fact that we have many components on vehicles now that draw significant power even when the vehicle is off.  Also- the alternator is simply a battery "maintainer" and is not meant for charging dead batteries.  A heavy load on the alternator such as when the battery is significantly depleted, often results in burning out the alternator.  Best thing for those who do not drive their vehicles daily/weekly is to get a battery maintainer/tender and plug it in when the vehicle is parked for awhile.  This also helps in the winter time for very cold climates in keeping the battery ready to go when starting up in the morning. 

I also use these on ATV/Snowblower batteries and where I was replacing the batteries in these applications every 2 years, I've extended beyond 6 in some cases. 

 

https://www.costco.com/battery-tender-4.5-amp-supersmart-battery-charger-%26-maintainer.product.100679769.html

 

[brianwhyman]

Wow...my first diesel truck and am in the learning stage.  My 2020 GMC AT4 3.0 would not start after being gone one week.  Jump started (barely) but would not restart.  So wheels were locked making the tow much more challenging to avoid damage.  Problem...bad battery!  So it was replaced.  I was told diesel engines require two batteries but I could only locate one.

 

Did I mention this is my 1st diesel...owners manual did not mention a 2nd battery and finding info on the web provided nothing until I say this forum mention for the first time my vehicle has only one battery (thanks for educating me)!

 

Now each month I get a vehicle diagnosis emailed to me.  For the past 2 months it mentions low battery (service soon) notices.  We ******...supposedly this is a new battery so what is the deal...back to is there a 2nd battery causing the issue.

 

So around and around I go....After talking to a few much smarter than I they recommended hooking up a maintainer which I purchased and did last night.  Since I could only locate one battery I connected it and it did indicate the battery was low and proceeded to charge it full.  

 

So great...now I think I know something is draining the battery 24/7 slowly draining/killing (long term) the now known single battery.  The apparent fix is to plug it in but how often...every night, once a week, once a month?????  

 

Does not seem right for a $60k+ vehicle to be so poorly designed and sold.  

[shakenfake]

Sounds like you should take it to the dealer. You don't need two batteries just because it is a diesel lol

[JimCost2014]

5 hours ago, brianwhyman said:

Wow...my first diesel truck and am in the learning stage.  My 2020 GMC AT4 3.0 would not start after being gone one week.  Jump started (barely) but would not restart.  So wheels were locked making the tow much more challenging to avoid damage.  Problem...bad battery!  So it was replaced.  I was told diesel engines require two batteries but I could only locate one.

 

Did I mention this is my 1st diesel...owners manual did not mention a 2nd battery and finding info on the web provided nothing until I say this forum mention for the first time my vehicle has only one battery (thanks for educating me)!

 

Now each month I get a vehicle diagnosis emailed to me.  For the past 2 months it mentions low battery (service soon) notices.  We ******...supposedly this is a new battery so what is the deal...back to is there a 2nd battery causing the issue.

 

So around and around I go....After talking to a few much smarter than I they recommended hooking up a maintainer which I purchased and did last night.  Since I could only locate one battery I connected it and it did indicate the battery was low and proceeded to charge it full.  

 

So great...now I think I know something is draining the battery 24/7 slowly draining/killing (long term) the now known single battery.  The apparent fix is to plug it in but how often...every night, once a week, once a month?????  

 

Does not seem right for a $60k+ vehicle to be so poorly designed and sold.  

Welcome to the site.

 

Batteries from the factory are prone to not have a long life, it just happens.

 

You will receive messages from On Star for a period of time, until they clear out of the system, even though work has been done and completed, just an annoying flaw in their system.

 

If you do have a draw, why do you think that it would not drain two batteries? How low did your tender say it was? Did you try starting at that level to see if it would?

 

Two batteries are usually set up when you have numerous accessories that are going to be a huge draw on the electrical system, not just for a daily driver.