[danhackst]

Came back from a two week vacation, and my new HummerEV which was delivered mid-March is dead. Totally dead. Not even a spark of life. I will be calling the Dealer and GM on Monday.

** UPDATE ** Dealer replaced the defective 12V battery under warranty. Quick response by GMC and the dealer!!

 

[Pav_01]

explain your situation in full, what was the battery condition before leaving, what was the percentage at, were all the accessories turned off for sure,

provide proof with actual pictures and not of it in the dealership, confirm through the MyGMC app.

Is this a dead battery situation or no life at all dead car situation - as in even after trying to charge it it's dead.

What you're claiming here is bigger than just a malfunctioning / dead car, so before this leaves the forum and gets picked up by a news company, provide proof of the claim that there is no spark left in the car and what do you exactly mean by it.

this affects much more than just owners, GM management, shareholders and stock brokers will be heavily affected by this if this is true, so it's best to provide proof that GM's new technology is already malfunctioning.

View attachment 2219


Came back from a two week vacation, and my new HummerEV which was delivered mid-March is dead. Totally dead. Not even a spark of life. I will be calling the Dealer and GM on Monday. So much for the Green New Deal! Not ready for prime time I guess.

 

[Nebula1701]

They posted this in the Hummer Facebook group.... What they explain is very reminiscent of a dead 12V Battery.

Please read up the User manual on how to jump your Truck....

Page 347.

Here is a Direct Link to the manual if you can't find it: https://www.gmc.com/bypass/pcf/gma-...mmer_EV_OM_en_US_U_84867425C_2022MAR24_3P.pdf

Here is the Web Page with all the User information:

Manuals and Guides | Vehicle Support | GMC

<p>Explore GMC Vehicle's Owner Manuals and Guides to learn more about your vehicle and its many features.</p>

www.gmc.com

 

[danhackst]

explain your situation in full, what was the battery condition before leaving, what was the percentage at, were all the accessories turned off for sure,

provide proof with actual pictures and not of it in the dealership, confirm through the MyGMC app.

Is this a dead battery situation or no life at all dead car situation - as in even after trying to charge it it's dead.

What you're claiming here is bigger than just a malfunctioning / dead car, so before this leaves the forum and gets picked up by a news company, provide proof of the claim that there is no spark left in the car and what do you exactly mean by it.

this affects much more than just owners, GM management, shareholders and stock brokers will be heavily affected by this if this is true, so it's best to provide proof that GM's new technology is already malfunctioning.

Battery was over 90% when I left on vacation. All accessories were off and the truck was not plugged into the charger. I believe it is the 12V starter battery that is dead, not the drive battery.

Proof of what? Picture of the truck in my garage? That is easy. Proof that it is dead? Not so easy. The MyGMC app is not communicating with the truck.

I don't think GMs new technology is malfunctioning, but neither do I think it is reasonable for a brand new vehicle to have a dead battery so soon.

 

[danhackst]

They posted this in the Hummer Facebook group.... What they explain is very reminiscent of a dead 12V Battery.

Please read up the User manual on how to jump your Truck....

Page 347.

Here is a Direct Link to the manual if you can't find it: https://www.gmc.com/bypass/pcf/gma-...mmer_EV_OM_en_US_U_84867425C_2022MAR24_3P.pdf

Here is the Web Page with all the User information:

Manuals and Guides | Vehicle Support | GMC

<p>Explore GMC Vehicle's Owner Manuals and Guides to learn more about your vehicle and its many features.</p>

www.gmc.com

Thanks. I will let GMC/Dealer bring the truck back to life. I don't want to risk damaging anything.

 

[Nebula1701]

As a Volt owner we live by ABC (Always be charging) plugging the vehicle into an outlet can help maintain your 12V battery as well, the car will maintain a proper voltage.

From the Hummer manual:

 

[Dark-Fx]

Just jump the 12V battery like you would an ICE.

 

[Gsolct]

Wait why is there a 12V…. Fine I’ll just google it.

Edit: ok, I get it that makes sense. Is it an actual 12V lead acid.

Was it in the frunk pic up over the passenger side over all those loops of tubing?

 

[Dark-Fx]

Wait why is there a 12V…. Fine I’ll just google it.

Edit: ok, I get it that makes sense. Is it an actual 12V lead acid.

Was it in the frunk pic up over the passenger side over all those loops of tubing?

It's under the panel next to the tub.

 

[Littleshopofguitars]

Why does it need a starter battery like that?

 

[Dark-Fx]

Why does it need a starter battery like that?

Most of the electronics run off of 12V and the HV battery is disconnected when not in use. The vehicle will periodically connect the HV battery to top up the 12V

 

[Duplantisjj]

While this battery drain during extended non-use issue does seem preventable at home by just keeping it plugged up, this does bring up a possible issue for people who may need to travel and leave the truck parked at airports for extended periods. I know that Teslas have ways of turning off certain battery draining functions and essentially putting the car to sleep with very little power drain. I've seen videos where they parked the Tesla at the airport for a week and had less than 1% battery drain (on the main drive battery not the 12 volt) but I wonder if GM has certain steps to go through that turns certain functions off if you plan to park it for some time without being plugged in?

 

[Dark-Fx]

While this battery drain during extended non-use issue does seem preventable at home by just keeping it plugged up, this does bring up a possible issue for people who may need to travel and leave the truck parked at airports for extended periods. I know that Teslas have ways of turning off certain battery draining functions and essentially putting the car to sleep with very little power drain. I've seen videos where they parked the Tesla at the airport for a week and had less than 1% battery drain (on the main drive battery not the 12 volt) but I wonder if GM has certain steps to go through that turns certain functions off if you plan to park it for some time without being plugged in?

Over the course of a week, when I left mine unplugged it didn't use even 1% of the battery

 

[travwill]

Likely the 12v., that’s what all electronics in cabin use etc. did you have it plugged in as well?

same situation very common in Teslas over the years but at least now they have switch to a 12v lithium ion custom battery now.

 

[azbill]

While this battery drain during extended non-use issue does seem preventable at home by just keeping it plugged up, this does bring up a possible issue for people who may need to travel and leave the truck parked at airports for extended periods. I know that Teslas have ways of turning off certain battery draining functions and essentially putting the car to sleep with very little power drain. I've seen videos where they parked the Tesla at the airport for a week and had less than 1% battery drain (on the main drive battery not the 12 volt) but I wonder if GM has certain steps to go through that turns certain functions off if you plan to park it for some time without being plugged in?

I have left my Bolt at the airport for a week at a time and never had an issue, nor did I have to turn anything off. These EVs use AGM batteries, not lead acid, and are supposed to have less phantom drain. But many EVs do seem to have 12V issues.

 

[danhackst]

Likely the 12v., that’s what all electronics in cabin use etc. did you have it plugged in as well?

same situation very common in Teslas over the years but at least now they have switch to a 12v lithium ion custom battery now.

Didn't have it plugged in.

 

[Tom E-Tron]

While this battery drain during extended non-use issue does seem preventable at home by just keeping it plugged up, this does bring up a possible issue for people who may need to travel and leave the truck parked at airports for extended periods. I know that Teslas have ways of turning off certain battery draining functions and essentially putting the car to sleep with very little power drain. I've seen videos where they parked the Tesla at the airport for a week and had less than 1% battery drain (on the main drive battery not the 12 volt) but I wonder if GM has certain steps to go through that turns certain functions off if you plan to park it for some time without being plugged in?

Teslas used to go dead all the time, they have worked on their algorithms and fixed most of the issues, but tesla's left to sit are still a bit hit and miss. Seems to me its better to follow the manufactures advise and leave it plugged in when out of town.

Hyundai Ioniq 5, have been going dead too when left parked.

 

[Littleshopofguitars]

My 2008 corvette would go dead in 14 days if not used, took it back to the dealer a half dozen times they chalked it up to, its a problem with about 25% of the Corvettes that year and we can not figure it out! Here is a new battery!!!

Sold It!

 

[Edge Case]

Why does it need a starter battery like that?

To run the low voltage systems; The radio, AC, seat heaters and coolers. All the stuff that are in ICE cars that they do not want and cannot afford to remake to run off a 400V architecture. This is a common problem in EVs. The best solution is to have a lithum Ion 12 Volt battery.

 

[theflew]

To run the low voltage systems; The radio, AC, seat heaters and coolers. All the stuff that are in ICE cars that they do not want and cannot afford to remake to run off a 400V architecture. This is a common problem in EVs. The best solution is to have a lithum Ion 12 Volt battery.

It's not about affordability, it's just no practical. You wouldn't want the main traction battery always connected. You might go to higher voltages for the types of things you mentioned. Something like 48V, but no one is talking about 400V.