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I have been browsing this forum for a while now and every so often someone says something about a low battery. I have a couple of 3 year old cars and I never have any low battery issues. Now these cars are driven perhaps more frequently than some of your Vettes as yours maybe are weekend cars or just not driven as much. Is this the reason or do the C8’s need need to be on chargers for some reason?
100+ micro processors, OnStar module and cellular radio / modem, wifi radio, etc etc.
Not sure I have ever seen details on what the C8 does when it is "sleeping". Does it wake up periodically to check GPS position and call home? Does it do this once every hour, or once every day when sleeping???
If you read all the threads and subthreads on this, you'll find that GM in their infinite wisdom has decided to trade 0.1 mpg for charging the battery. Concisely, If you do not have (keep) it on a charger when parked at "home", you'll be lucky to get 12-24 months from the OEM and subsequent batteries. Otherwise it will live in the 30+% (12.5Vdc) discharged range.
There are just all kinds of gizzmos running 24-7 in a Vette.
Originally Posted by dohabandit
100+ micro processors, OnStar module and cellular radio / modem, wifi radio, etc etc.
It started with the C6. That car had 20 microprocessors in it and if you read the C6 section of this forum you'll see that most owners keep their C6 on a battery tender/maintainer. The C7 has 70 microprocessors in it, but in the four years that I owned one I never had a battery issue, never kept it on a battery tender/maintainer, and it still had the original battery in it when I sold it.
I think the majority of the battery issues in the C8 - from reading posts about it in this forum - are caused by the over the air updates. The good thing is that the C8 has a power port in the frunk that you can plug a battery maintainer into and you shouldn't have a problem. I bought one for my C8 and plug it in every time I park it.
Most battery maintainers only put out 1.5 amps, which is not near enough to keep the battery charged if the Over the Air update locks up and leaves some or all the accessories running. Just be aware. We bought one at the Corvette Museum and its only rated at 1.5 amps. They are designed to extend battery life by helping reduce the sulfating of the lead plates. Read up on what they were intended to do.
Yes, I use a maintainer but have a regular charger that has a 5 amp output. When the OTA update failed a few months ago on my car and drained the battery, I charged it with that and it took a good 6 hours to bring it back up to normal. A battery maintainer wouldn't do it in that situation.
The battery issues are not unique to Corvettes. Any new premium car.truck or bike will have similar electronics and therefore battery requirements
NOT TRUE!
My 2021 GMC Acadia does alternator charging as it is supposed to be done. Bulk, Acceptance, Float as necessary while driving (engine running). It doesn't make logical sense in that there are more GMC SUVs than C8s being produced & the C8 gets better mileage to start with. Contrary to the 0.1pg reasoning stated by most, my gut tells me it is a HP thing.
If you read all the threads and subthreads on this, you'll find that GM in their infinite wisdom has decided to trade 0.1 mpg for charging the battery. Concisely, If you do not have (keep) it on a charger when parked at "home", you'll be lucky to get 12-24 months from the OEM and subsequent batteries. Otherwise it will live in the 30+% (12.5Vdc) discharged range.
My C7 used the same charging scheme as the C8. I never put my C7 on a maintainer. The battery was still working after nearly 5 years when I got rid of the car.
100+ micro processors, OnStar module and cellular radio / modem, wifi radio, etc etc.
Not sure I have ever seen details on what the C8 does when it is "sleeping". Does it wake up periodically to check GPS position and call home? Does it do this once every hour, or once every day when sleeping???
Someone (i think it was @Andybump ) put an amp meter on the battery. The discharge rate was pretty low when the car was sleeping. There is also a description of what/when the car wakes floating around the forum somewhere.
I think the majority of the battery issues in the C8 - from reading posts about it in this forum - are caused by the over the air updates.
Agreed. Best solution is to buy a CTEK battery charger (not a trickle charger) from Amazon with a cigarette plug adapter. Costs less than the GM trickle charger and provides much more functionality.
NOT TRUE!
My 2021 GMC Acadia does alternator charging as it is supposed to be done. Bulk, Acceptance, Float as necessary while driving (engine running). It doesn't make logical sense in that there are more GMC SUVs than C8s being produced & the C8 gets better mileage to start with. Contrary to the 0.1pg reasoning stated by most, my gut tells me it is a HP thing.
I'll assume your Acadia is daily driven. Park it for 3 weeks then we'll talk !
NOT TRUE!
My 2021 GMC Acadia does alternator charging as it is supposed to be done. Bulk, Acceptance, Float as necessary while driving (engine running). It doesn't make logical sense in that there are more GMC SUVs than C8s being produced & the C8 gets better mileage to start with. Contrary to the 0.1pg reasoning stated by most, my gut tells me it is a HP thing.
That's funny my 2015 Buick Regal had the same type charging system as the C8 and only made it to 180,000 miles on the battery (that's when it was sold, still working fine). So GM uses this same type of charging as the C8 has on all its cars except a 2021 Acadia???? Is that because they have learned the error of their ways or you're simply mistaken on how it works?
My 2021 C8 battery lasted 40 days from the time I took delivery at the NCM on Sept 7, 2021 - she was built on July 30, 2021 - I had it replaced at a local Chevy dealership in Newport News Virginia, under
warranty. Since then no issues, but I'm driving her daily. She not sitting for long periods 2021 C8 Ceramic Coating 9 12 21
If you read all the threads and subthreads on this, you'll find that GM in their infinite wisdom has decided to trade 0.1 mpg for charging the battery. Concisely, If you do not have (keep) it on a charger when parked at "home", you'll be lucky to get 12-24 months from the OEM and subsequent batteries. Otherwise it will live in the 30+% (12.5Vdc) discharged range.
Many of the Auto batteries are made in Mexico and are crap. They start to have issues at 3 years and that is when I pull them out and replace. Cheap insurance.
Last edited by kong; 10-23-2021 at 07:46 PM.
Reason: correction
Normally the car doesn't need a charger. The systems power down into a minimum power sleep state when doors are locked.
What has happened to me once is that the over the air update stalled or put the car in a limbo state which prevented it from going to sleep. Everything stayed powered and it killed the battery in 24hrs. Parking the car outside and repeating the update seamed to clear this.
I have a feeling that people who experienced battery issues also experiences some anomaly condition which left the car electronics in a full power state for an extended period of time with the engine off.
This is abnormal and a bug, not a feature. I don't use a charger and don't plan on it. Since the issue the car sits for up to a month at a time with no reoccurrence.
My C8 sat for 2 weeks... Hopped in it and fired right up like it has been driven 5 minutes prior. Similar in my C7, it could sit for a month and no problem; battery lasted 5+ years. People on this forum spend more time worrying about make believe issues then actually driving their cars.
I haven't heard on the C8 yet, however on my Porsche and Maserati when you lock the doors the car goes into a sleep mode, My local Porsche dealer stressed that when the car is setting for long periods of time in the garage to make sure the doors are locked.
I'll assume your Acadia is daily driven. Park it for 3 weeks then we'll talk !
Originally Posted by Phil1098
That's funny my 2015 Buick Regal had the same type charging system as the C8 and only made it to 180,000 miles on the battery (that's when it was sold, still working fine). So GM uses this same type of charging as the C8 has on all its cars except a 2021 Acadia???? Is that because they have learned the error of their ways or you're simply mistaken on how it works?
Such science deniers. Do it for yourself. Drive your C8 anywhere. Park....wait 5 minutes and restart - and it still won't charge out of the 12.5 zone for more than a few seconds after start.
Btw, Acadia is GM, not Chevrolet. . AND YES NOT ALL OF GM USES THE SAME PARTS OR DESIGN INCLUDING CHEVROLET. Btw, I don't post opinions as facts unlike some that I just ignore.
I’ve had dozens of cars of different males and models over the years and the only car with serious battery issues seemed to be my C5. Even on a new battery that thing would start throwing electrical gremlins by the end of the week if not driven. I learned to keep it on a charger and all problems went away. The excuse at the time was “it’s a sophisticated machine packed full of modern technology” lol.
Browsing the C6 forums looks like the problem didn’t get any better, Since then I’ve had far more complicated vehicles that have sat for weeks with no issue.
A couple exceptions (more related to battery life vs sporadic draining while parked) were both convertibles that only got 3 years out of a battery. I got them both used and I suspect the previous owners raised and lowered the tops with the battery.
When I started reading up on C8’s it was no surprise battery threads starting popping up. It could be GM doesn’t have enough safeguards from killing the battery or hung up over the air updates, or too much load just before turning off (My front end lift raises as I approach my driveway followed by me raising the top. I’m probably starting habits that will shorten battery life)
10-22-2021, 10:38 AM
Battery Issues??
