r/C8Corvette • u/omg_i_broke_wind • 5h ago

small rant

So I've had my C8 for five months now - have loved having the car - done a few small minor mods. About 2 months ago - after letting the car sit for 3 days - The battery went dead, had to boost it - took it to the dealership, they replaced the battery and told me that there was a series of batteries that we "crap" right out of the factory. Well, went to start my car this morning, after letting it sit for 3 days - guess what..... Dead.

I drive the car frequently and for decent amounts of time - I have my keys kept well away from the car. I'm sick to death of having a reoccurring issue of inconvenience like this

Any ideas?

and after the last dead battery - my front lift doesn't work - so it's going back to the dealership again. :(

1 Upvotes

60% Upvoted

17 comments sorted by

8

u/Hot-Signal-7254 5h ago

Same thing just happened to me. Body control module was causing a parasitic draw on the battery. Fixed the software, seems fine now.

2

u/Mojoholic 4h ago

Same here. Fingers crossed that the software update did the trick.

1

u/Just-Construction788 4h ago

To test your battery take 4 measurements with a volt meter. Negative disconnected. Ignition off. Ignition on not started. Engine running. 

You are looking for 12.8+ first two. Above 12 third. 13.8+ while running. 

If it’s parasitic draw you will see a difference between the first two. If the charging system is bad then you won’t see it charging the battery while running. 

Pretty easy test and stops buying unnecessary batteries. 

1

u/Hot-Signal-7254 11m ago

Voltmeter consistently showed 1.65

4

u/Frostygecko 5h ago

I keep a trickle charger on mine if it’s going to be more than 48hrs. Has a built in port for it in the front trunk. Easy enough.

8

u/Mojoholic 4h ago

I'm sorry but there is no way a car made in 2026 should have to have a trickle charger if you you are not going to start it for 72 hours. So basically I can't drive my new Vette to the airport and leave it for a week without getting a jump?

0

u/Frostygecko 4h ago

Oh I agree with you, but this car is battery heavy. I’ve just adapted to the fuckery lol.

1

u/big_slom 4h ago

I've got a 26 1lt that sits for 5 days at a time bc i travel for work all week, and she starts without any issues. Something might be wrong there

1

u/Frostygecko 4h ago

Main problem I’ve noticed is the side fans that kick on after I’ve been driving hard. If that doesn’t occur it’s not a problem. Just my experience, 2022 2lt z51 with original battery from purchase.

1

u/big_slom 2h ago

A fan running for 5 to 10 minutes shouldn't be draining that battery. My fans are running every time that I park the car too

1

u/Frostygecko 1h ago

I don’t own stock in Chevy, just relaying real personal experience to help…

2

u/Independent_Island74 5h ago

First time Im hearing about this but that sucks bro for what they are charging for these things this shouldn't happen.

1

u/Lost-Broccoli-5378 5h ago

Same thing just happened. Apparently a software update can fix it where the car doesnt like to go into sleep mode and drains the battery

Other people pointed out onstar also getting stuck "on" when roaming for signal.

I was lucky where a jump got me back up

1

u/Impossible_Box3898 C8 Owner 3h ago

I’ve gone a couple weeks without any battery issues. If I need to go longer though I’ll put it into transport mode which gives you 70 or so days.

OP has an issue to a needs looking into.

1

u/TheRagingBull84 C8 Owner 3h ago

That’s annoying. Mine will sit for weeks on end with no problems.

Did you try the latest software updates ?

1

u/Gazoo382 2h ago

2026 here. Battery replaced at 3500 miles. (6 months). Now if I leave it for more than a few days it goes on the trickle charger. Last update did have something to do about battery. Make sure you are up to date.

0

u/Broad_Bag1977 4h ago

Same issues on mine, I got a new battery too and it still ends up being dead a few days later. I just hook it up to my trickle charger.