computer battery drain question
Thread Starter
Advanced
Joined: Nov 2020
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From: The Villages, FL
Team Owner
Joined: Jul 2004
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From: Hartford WI
Race Director
Joined: Apr 2007
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From: Toronto, Canada
C7 of the Year - Unmodified Finalist 2021
Melting Slicks
Joined: Mar 2013
Posts: 3,104
Likes: 626
From: Baton Rouge LA
Same here, even when I know I'll be driving it again the next day. Lead-acid batteries typically last longer when specific gravity is kept at optimum--i.e., fully changed.
Drifting
Joined: Nov 2014
Posts: 1,978
Likes: 110
From: Switzerland
so, typically there will be a draw of mabe 1 amp after switching ignition off. it will the go down is several steps, as eg interior lights go off, etc. after a few minutes i see 8 mili amps constant draw. thats how it is on my car.
if you see considerably more than 8 mili amps, you shoul start checking. pulling fuses might be the simplest way.
(dont waste your money going to a shop, imo.)
edit: connect a multimeter between one of the battery terminals and the corresponding cable. sett it to 1 amp, then switch to 100 mili amps as the current falls. should be easy.
if you see considerably more than 8 mili amps, you shoul start checking. pulling fuses might be the simplest way.
(dont waste your money going to a shop, imo.)
edit: connect a multimeter between one of the battery terminals and the corresponding cable. sett it to 1 amp, then switch to 100 mili amps as the current falls. should be easy.
Drifting
Joined: Aug 2022
Posts: 1,552
Likes: 1,681
From: Cincinnati, OH
I've had mine for 6 years now. Replaced the battery at 4 years just because it was 4 years old. I try to drive mine at least once a week all year. If its going to sit for 2 weeks or more, I plug in the trickle charger just because it there and why not?
No issues.
Since I use the charger so infrequently, I take the black bag that my charger came in and hang it over the shift **** as a reminder to disconnect before pulling out of the garage
No issues.
Since I use the charger so infrequently, I take the black bag that my charger came in and hang it over the shift **** as a reminder to disconnect before pulling out of the garage
Melting Slicks
Joined: Feb 2018
Posts: 2,172
Likes: 1,041
From: North Texas
My 2017 GS is sitting this winter. 
I have a battery maintainer. So I "charged up" the battery with the maintainer for a week or so, disconnected the battery maintainer, and measured battery voltage at 13.0 volts. Good. I let the car sit for a week without the maintainer and the battery voltage drooped to 12.3 volts. I was rather surprised. My new battery was installed the first week in July of this year. I suspect with all the electronic systems in the C7 there is a significant parasitic energy drain. I'll bet that's why Corvette provided such a coinvent connection for a battery maintainer as they knew Corvettes aren't great on winter slick roads.
Others more knowledgeable than I will surely chime in.
David
I have a battery maintainer. So I "charged up" the battery with the maintainer for a week or so, disconnected the battery maintainer, and measured battery voltage at 13.0 volts. Good. I let the car sit for a week without the maintainer and the battery voltage drooped to 12.3 volts. I was rather surprised. My new battery was installed the first week in July of this year. I suspect with all the electronic systems in the C7 there is a significant parasitic energy drain. I'll bet that's why Corvette provided such a coinvent connection for a battery maintainer as they knew Corvettes aren't great on winter slick roads.Others more knowledgeable than I will surely chime in.
David
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Instructor
Joined: Apr 2024
Posts: 203
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From: Reston VA
I got Costco battery. Works great. There are only 3 manufacturers that make batteries and rebranded. Buy the one that's cheap.
I had the battery drain too. I thought it was the security system that drained it, the one that senses when people get in your car without key with the top down. Either that, it's the alternator not being able to charge enough because you don't drive enough/long enough.
I had the battery drain too. I thought it was the security system that drained it, the one that senses when people get in your car without key with the top down. Either that, it's the alternator not being able to charge enough because you don't drive enough/long enough.
Le Mans Master
Joined: Oct 2005
Posts: 7,002
Likes: 2,679
FYI this isn't a Corvette unique thing.
The number one warranty item at GM, Ford, and Chrysler right now? Batteries.
Modern cars with many many computers have all sorts of KOL (Key Off Load) problems and Quiescent Current issues. If you leave any modern car parked for 2+ Weeks you are damaging your battery SOC and if you go longer than 4 Weeks (or regularly leave it 2+) you should put it on a battery tender.
There is a two fold reason for this, one the modules drain energy constantly, but usually very very low and two the car wakes up almost everything everytime you open a door, truck, etc causing them to be awake for 1-2 minutes (should be less but sometimes modules misbehave) until after you close the door/trunk and walk away. If your car has approach detection or anything else fancy it does this anytime you get near it with your key.
So yea, if you don't daily drive, setup a battery tender. I have one in each spot in my garage.
The number one warranty item at GM, Ford, and Chrysler right now? Batteries.
Modern cars with many many computers have all sorts of KOL (Key Off Load) problems and Quiescent Current issues. If you leave any modern car parked for 2+ Weeks you are damaging your battery SOC and if you go longer than 4 Weeks (or regularly leave it 2+) you should put it on a battery tender.
There is a two fold reason for this, one the modules drain energy constantly, but usually very very low and two the car wakes up almost everything everytime you open a door, truck, etc causing them to be awake for 1-2 minutes (should be less but sometimes modules misbehave) until after you close the door/trunk and walk away. If your car has approach detection or anything else fancy it does this anytime you get near it with your key.
So yea, if you don't daily drive, setup a battery tender. I have one in each spot in my garage.
Heel & Toe
Joined: Aug 2023
Posts: 15
Likes: 4
From: Mt Juliet, TN
C7 battery drain noticeable after sitting 7 - 10 days. I have maintainer generally used in winter. Plan to use more often.
Question: as battery attach plug is in trunk, is best approach to plugging maintainer to AC outlet to run cord out of trunk and close trunk hatch (easily) on cord so all interior lights cancel?
Question: as battery attach plug is in trunk, is best approach to plugging maintainer to AC outlet to run cord out of trunk and close trunk hatch (easily) on cord so all interior lights cancel?
Burning Brakes
Joined: Apr 2018
Posts: 885
Likes: 487
I am thinking of replacing it before I store the car for the winter. But, I said that last year
Team Owner
Joined: Jul 2004
Posts: 28,462
Likes: 3,288
From: Hartford WI
The number one warranty item at GM, Ford, and Chrysler right now? Batteries.
Modern cars with many many computers have all sorts of KOL (Key Off Load) problems and Quiescent Current issues. If you leave any modern car parked for 2+ Weeks you are damaging your battery SOC and if you go longer than 4 Weeks (or regularly leave it 2+) you should put it on a battery tender.
There is a two fold reason for this, one the modules drain energy constantly, but usually very very low and two the car wakes up almost everything everytime you open a door, truck, etc causing them to be awake for 1-2 minutes (should be less but sometimes modules misbehave) until after you close the door/trunk and walk away. If your car has approach detection or anything else fancy it does this anytime you get near it with your key.
So yea, if you don't daily drive, setup a battery tender. I have one in each spot in my garage.
Modern cars with many many computers have all sorts of KOL (Key Off Load) problems and Quiescent Current issues. If you leave any modern car parked for 2+ Weeks you are damaging your battery SOC and if you go longer than 4 Weeks (or regularly leave it 2+) you should put it on a battery tender.
There is a two fold reason for this, one the modules drain energy constantly, but usually very very low and two the car wakes up almost everything everytime you open a door, truck, etc causing them to be awake for 1-2 minutes (should be less but sometimes modules misbehave) until after you close the door/trunk and walk away. If your car has approach detection or anything else fancy it does this anytime you get near it with your key.
So yea, if you don't daily drive, setup a battery tender. I have one in each spot in my garage.
Most interesting question would be "How worth it is daily plugging in?". Battery is about $200 so how much life are you really saving by plugging in whenever it is not driven? I agree that after a couple of weeks we could have a problem but I wouldn't bother to plug it in when it isn't driven.
Le Mans Master
Joined: Oct 2005
Posts: 7,002
Likes: 2,679
Not sure where you read that so let me ask. Did that article say why? A lot of them sit in the engine bay and are heat-cold cycled very often which can't be good for the battery. It is also shook around and the acid sloshing against the plates might also be an issue.
Most interesting question would be "How worth it is daily plugging in?". Battery is about $200 so how much life are you really saving by plugging in whenever it is not driven? I agree that after a couple of weeks we could have a problem but I wouldn't bother to plug it in when it isn't driven.
Most interesting question would be "How worth it is daily plugging in?". Battery is about $200 so how much life are you really saving by plugging in whenever it is not driven? I agree that after a couple of weeks we could have a problem but I wouldn't bother to plug it in when it isn't driven.
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
This is what I do as well. Plug it in and close the hatch. Never had any issues with this method. You don't have to worry about leaving the hatch open because the interior lights are on a timer and will shut off automatically after about 15 min. I close my hatch to help prevent any 4 or 8 legged critters from getting in.
Advanced
Joined: Jun 2023
Posts: 65
Likes: 27
I replaced the original battery in my C7 (2016) as a precaution last year. I would often go a week or two without driving the car. Even with a 7-year-old battery, I have never had any problems, and I have never attached a trickle charger to the car. I would be concerned if your 4-year-old battery didn't start the car after a week or so.
Last edited by SoCalDavid; Nov 17, 2024 at 02:21 AM. Reason: spelling