Battery drain - Why?
Thread Starter
Instructor
Joined: Nov 2009
Posts: 122
Likes: 1
From: Manhattan KS
Battery drain - Why?
Hello Forum,
I am a newbie and have perused the forum regarding battery tenders and the like. I experienced the deadly "click click click" last month after only one week or so of non-use. I went ahead and purchased a tender from the National Corvette Museum and after a day or so the red light on the tender went to green.
One simple question. Why do Corvettes have significant battery drain? What components are pulling a charge when the car is not being used?
This is probably a really stupid question.
Thank you in advance!
I am a newbie and have perused the forum regarding battery tenders and the like. I experienced the deadly "click click click" last month after only one week or so of non-use. I went ahead and purchased a tender from the National Corvette Museum and after a day or so the red light on the tender went to green.
One simple question. Why do Corvettes have significant battery drain? What components are pulling a charge when the car is not being used?
This is probably a really stupid question.
Thank you in advance!
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Either your battery is on its last legs or there is a higher-than-normal electrical drain. Also, you should never use a battery tender to charge a dead battery. Those "tenders" are designed to keep a battery charged, not charge it from nothing. An automatic "charger" is the thing to use if your battery is dead or near dead.
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Its a difficult question to answer.
What use does you car get? Is it a DD in which case the battery should recharge. If it's only used for short trips at weekends then each start drains the battery and it never gets the chance to get fully recharged
There are a few components that cause a drain. People leave Ipods and radar detectors plugged in. Its possible to leave the interior lights on. So many minor things that just run an already tired battery down. The seat motors are notorious for sticking and killing the battery.
If you have an 01-03 you may have an AGM battery which is intolerant to drain.
As I always say, best go for a battery tender before you have the problem and you can sleep easy.
HTH
What use does you car get? Is it a DD in which case the battery should recharge. If it's only used for short trips at weekends then each start drains the battery and it never gets the chance to get fully recharged
There are a few components that cause a drain. People leave Ipods and radar detectors plugged in. Its possible to leave the interior lights on. So many minor things that just run an already tired battery down. The seat motors are notorious for sticking and killing the battery.
If you have an 01-03 you may have an AGM battery which is intolerant to drain.
As I always say, best go for a battery tender before you have the problem and you can sleep easy.
HTH
Last edited by DeeGee; Jan 13, 2010 at 02:58 PM.
Drifting
Joined: Jul 2007
Posts: 1,365
Likes: 1,818
With a battery in good condition to begin with and no abnormal drains from things like IPODS left on, stuck lumbar motors, etc the battery should last a month or more without being on a tender device. When the BCM goes into sleep mode the drain to the battery should be less than 20 ma. My 04 CE vert sat for 4 weeks over the recent holidays and when I got in to start it up it fired up with no problems. I did drive the car continuously for more than an hour on the first trip so I most likely got the battery charged back up pretty well.
As DeeGee has suggested if your car only gets short trips when you do take it out you are probaby draining more from the battery to start it up than you put back in while driving.
There are many known devices on the C5 that get "stuck" and can drain the battery quickly and that is probably one of the major reasons so many use the tender devices when the car sits for more than a few days. Also some aftermarket add-ons cause drain in addition to the 20ma drain of the stock C5 when the BCM goes into sleep mode.
As DeeGee has suggested if your car only gets short trips when you do take it out you are probaby draining more from the battery to start it up than you put back in while driving.
There are many known devices on the C5 that get "stuck" and can drain the battery quickly and that is probably one of the major reasons so many use the tender devices when the car sits for more than a few days. Also some aftermarket add-ons cause drain in addition to the 20ma drain of the stock C5 when the BCM goes into sleep mode.
