Battery drain problem.

[Jimmy]

I'm having problems with my C5,battery keeps going flat.I think it might be the alarm,i hadn't used it for a couple of weeks and it fired up right away until i took it for an MOT.When i went to collect my Corvette the MOT bloke set the alarm off by accident,he turned it off using the fob but now theres a battery drain.I'm gonna have to start pulling fuses to try and sort it myself.
The sad news is i'm going to have to sell,my knees and back are getting worse and i'm struggling to get in and out of it.It's mostly stood on the driveway now,it's a shame really it's a nice looking car in all black.
It's got a new 12 month MOT,193,000 miles on the clock,heads up display,semi convertable,automatic,few upgrades ,exhaust,air intake,harmonic ballancer.I've just not a clue as to what price i should ask for a quick sale,i really need a car i can get in and out of.Any advice welcome.Thanks.

 

[teamzr1]

Since there are several controllers in vehicles that can drain the battery,
Corvettes since the C5 really need a battery tender connected when not driving it for days
I suggest first is doing a battery load test as once they get too low on voltage they never really fully charge back up and could have at least 1 cell degraded

Once the controllers have gone to sleep, about 10 minutes after turning off, current load should be below 0.50 mAmps
If higher than, you will have to debug what circuit is doing the draw
There are cheap D/C AMP and relay testers that would help to track down which circuit is at fault
Few of the ones I have tested and work OK

 

[Jimmy]

Since there are several controllers in vehicles that can drain the battery,
Corvettes since the C5 really need a battery tender connected when not driving it for days
I suggest first is doing a battery load test as once they get too low on voltage they never really fully charge back up and could have at least 1 cell degraded

Once the controllers have gone to sleep, about 10 minutes after turning off, current load should be below 0.50 mAmps
If higher than, you will have to debug what circuit is doing the draw
There are cheap D/C AMP and relay testers that would help to track down which circuit is at fault
Few of the ones I have tested and work OK

View attachment 26554

I have a solar panel plugged in,that did it's job until the mot man got his hands on my car and set the alarm off.I have a tester,thanks for the info on the controllers and the 0.5 amp draw.

 

[teamzr1]

Maybe disconnect one side of battery for like 10 minutes and then connect again to get everything to reboot and maybe
clear the current draw

 

[oelarse]

I recommend to measure votage over every fuse in engineroom and passenger footwell setting the multimeter on mV .
Open the passenger door and activate doorlock mechanisme while door is open and wait until BCM has gone to sleep (approx 15-20 min)

how to measure current draw from battery