Battery Drain
Thread Starter
Intermediate
Joined: Jul 2021
Posts: 29
Likes: 1
From: Deltona, FL
Battery Drain
I have the usual issues with battery drain. I just replaced my O Rieley's battery with a OPtima Red. The instructions showed how to test battery drain with engine off. Basically parked.
Disconnected the black battery cable and used a multimeter set on millivolts. The instructions said bleed should be no more than 100 mv. Not sure if that applies to Corvettes. The meter went off scale switched to 15 volt setting on multimeter and it reads from 9.5 to 10 volts. Started pulling fuses one at a time in box underhood and looked for that voltage read out to drop, it did not. This procedure is in the Optima battery literature.
Next I will check some fuses in the box inside the car. passenger side. Does anybody have a suggestion here on which fuses to check first or any other possible cause of this drain when parked? Does it just mean a short or frayed cable somewhere?
I Did check alternator voltage at battery with motor running and that was around 15 V.
Car is 2000 and 6 speed manual. No after market accessories installed.
Todd
Disconnected the black battery cable and used a multimeter set on millivolts. The instructions said bleed should be no more than 100 mv. Not sure if that applies to Corvettes. The meter went off scale switched to 15 volt setting on multimeter and it reads from 9.5 to 10 volts. Started pulling fuses one at a time in box underhood and looked for that voltage read out to drop, it did not. This procedure is in the Optima battery literature.
Next I will check some fuses in the box inside the car. passenger side. Does anybody have a suggestion here on which fuses to check first or any other possible cause of this drain when parked? Does it just mean a short or frayed cable somewhere?
I Did check alternator voltage at battery with motor running and that was around 15 V.
Car is 2000 and 6 speed manual. No after market accessories installed.
Todd
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From: Cape Coral, Florida
Welcome to the Forum !!…Try disconnecting the B+ cable on the alternator !!…the car should draw no more than 25 Milliamps when all the modules go to sleep !!..don’t pull fuses…watch the video below…you check the drain on the milliamps scale between the battery post and cable…You check the fuses on the millivolt scale on the lowest setting…It’s a good idea to fill out your profile..model year, mods, tune ???, your location.
Last edited by C5 Diag; Jul 6, 2021 at 08:02 PM.
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Thread Starter
Intermediate
Joined: Jul 2021
Posts: 29
Likes: 1
From: Deltona, FL
thank you Mickey
Welcome to the Forum !!…Try disconnecting the B+ cable on the alternator !!…the car should draw no more than 25 Milliamps when all the modules go to sleep !!..don’t pull fuses…watch the video below…you check the drain on the milliamps scale between the battery post and cable…You check the fuses on the millivolt scale on the lowest setting…It’s a good idea to fill out your profile..model year, mods, tune ???, your location.
https://youtu.be/lRcj1fQcWwU
https://youtu.be/lRcj1fQcWwU
Safety Car
Joined: Mar 2017
Posts: 3,755
Likes: 934
From: Orlando Florida
My drain ended up being the auto entry positioning of the driver seat. Seat would try to go all the way back, stall without making noise, and kill the battery in about 5 days. Turned off the auto assist and battery lasts a week or more.
Cruising
Joined: Feb 2020
Posts: 11
Likes: 1
From: Newnan, GA
Hello - you should be checking for battery drain with the amp/milliamp setting on the multimeter and not voltage. I can't remember exactly but if I recall correctly mine will go from something like 7 amps to 3 amps to around 1.5 amps within a minute or two and then go below one amp shortly thereafter and gets below 100 milliamps. I spent a ton of time tracking down a parasitic draw problem a year or so ago so I'm happy to help. Do some searches on this forum for parasitic draw - they are fantastic resources for tracking them down.
Thread Starter
Intermediate
Joined: Jul 2021
Posts: 29
Likes: 1
From: Deltona, FL
Hello - you should be checking for battery drain with the amp/milliamp setting on the multimeter and not voltage. I can't remember exactly but if I recall correctly mine will go from something like 7 amps to 3 amps to around 1.5 amps within a minute or two and then go below one amp shortly thereafter and gets below 100 milliamps. I spent a ton of time tracking down a parasitic draw problem a year or so ago so I'm happy to help. Do some searches on this forum for parasitic draw - they are fantastic resources for tracking them down.
Todd
