Notices
C5 General General C5 Corvette and C5 Z06 Discussion not covered in Tech

[Z06] Testing for battery drain

Thread Tools
 
Search this Thread
 
Old Oct 14, 2006 | 11:19 AM
  #1  
TAC's Avatar
TAC
Thread Starter
Drifting
20 Year Member
 
Joined: May 2000
Posts: 1,797
Likes: 0
From: Thompson Falls MT
Default Testing for battery drain

I would like to test my car to see if it's pulling more juice while just sitting there than it's supposed to. I have a multi-meter but never got around to learning how to use it. Is there a relatively easy instruction set on how to test my car's sitting electrical drain? TIA
Reply
Old Oct 14, 2006 | 11:39 AM
  #2  
LarryW's Avatar
LarryW
Pro
10 Year Member
 
Joined: Jul 2004
Posts: 710
Likes: 1
From: Fremont (Livin' On The Fault Line!) CA
Default

I came across this thread on the "other forum"; it provides an excellent illustration on how to hook up a meter to check for battery drain:

Battery Dies after 1.5 weeks in storage (see the 4th post down).

Per this diagram, the draw should not exceed 100 mA.

Larry
Reply
Old Oct 14, 2006 | 03:17 PM
  #3  
ZeeOSix's Avatar
ZeeOSix
Le Mans Master
20 Year Member
 
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Default

Originally Posted by LarryW
Per this diagram, the draw should not exceed 100 mA.
The parasitic battery current should be about 20 mA on the C5 Vette.

Do a search on the other site for "parasitic current" and you'll find some super detailed posts about how I tested mine. You have to wait about 20 minutes to let all the computers "go to sleep" before the parasitic drain goes down to 20 mA.
Reply
Old Oct 14, 2006 | 03:22 PM
  #4  
TAC's Avatar
TAC
Thread Starter
Drifting
20 Year Member
 
Joined: May 2000
Posts: 1,797
Likes: 0
From: Thompson Falls MT
Default

Originally Posted by LarryW
I came across this thread on the "other forum"; it provides an excellent illustration on how to hook up a meter to check for battery drain:

Battery Dies after 1.5 weeks in storage (see the 4th post down).

Per this diagram, the draw should not exceed 100 mA.

Larry
Great Instructions! I need some help with the results. With the hood light left in place when I hook up the meter the light comes on and I read 2.28A right away. After about 10 seconds the amperage drops to .345 A for a brief moment or two and then drops to .08 A. From there it holds steady. If I remove the hood light and then hook up the meter I read 1.24 A right away. After about 10 seconds the amperage again drops to .345 A for a brief moment or two and then drops to .08 A. Am I right in thinking all is well? Does .08 A equate to 80 mA? I can't ever try it with the meter set to 400mA because it draws too much to start with.

Thanks much for all the help. This forum is !
Reply
Old Oct 14, 2006 | 03:24 PM
  #5  
TAC's Avatar
TAC
Thread Starter
Drifting
20 Year Member
 
Joined: May 2000
Posts: 1,797
Likes: 0
From: Thompson Falls MT
Default

Originally Posted by ZeeOSix
The parasitic battery current should be about 20 mA on the C5 Vette.

Do a search on the other site for "parasitic current" and you'll find some super detailed posts about how I tested mine. You have to wait about 20 minutes to let all the computers "go to sleep" before the parasitic drain goes down to 20 mA.
I take it you had different type of meter leads? Mine are probe type. Do you tape them in place or something?
Reply
Old Oct 14, 2006 | 06:48 PM
  #6  
TAC's Avatar
TAC
Thread Starter
Drifting
20 Year Member
 
Joined: May 2000
Posts: 1,797
Likes: 0
From: Thompson Falls MT
Default

Originally Posted by ZeeOSix
The parasitic battery current should be about 20 mA on the C5 Vette.

Do a search on the other site for "parasitic current" and you'll find some super detailed posts about how I tested mine. You have to wait about 20 minutes to let all the computers "go to sleep" before the parasitic drain goes down to 20 mA.
I added my test results to your post on Z06vette.com. I'll add them here as well. Looks like my car is right on target with a final drain of .01-.02 A loss. Thats 10-20 mA, right?

XXXXXXXXXXXX

I did my own tests and here's my results. All stock '03 Z06

Everything functional - the hood was left up the entire time.

Time 0:00 Hood up and Doors Open - 6.8A

As soon as door closed - 5.40 A

+ 45 sec - 2.8 A hood light still on

+ 50 sec - 1.8 A hood light still on

+ 60 Sec - 1.1 A hood light still on

+ 10.5 Min - .08 A hood light goes off

+ 13 Min - 0.01/.02 A Everything apparently off
Reply
Old Oct 15, 2006 | 12:28 AM
  #7  
ZeeOSix's Avatar
ZeeOSix
Le Mans Master
20 Year Member
 
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Default

Originally Posted by TAC
I added my test results to your post on Z06vette.com. I'll add them here as well. Looks like my car is right on target with a final drain of .01-.02 A loss. Thats 10-20 mA, right?

XXXXXXXXXXXX

I did my own tests and here's my results. All stock '03 Z06

Everything functional - the hood was left up the entire time.

Time 0:00 Hood up and Doors Open - 6.8A

As soon as door closed - 5.40 A

+ 45 sec - 2.8 A hood light still on

+ 50 sec - 1.8 A hood light still on

+ 60 Sec - 1.1 A hood light still on

+ 10.5 Min - .08 A hood light goes off

+ 13 Min - 0.01/.02 A Everything apparently off
Looks normal to me.
Reply
Old Oct 15, 2006 | 08:17 AM
  #8  
TAC's Avatar
TAC
Thread Starter
Drifting
20 Year Member
 
Joined: May 2000
Posts: 1,797
Likes: 0
From: Thompson Falls MT
Default

I charged the Optima most the day yesterday on the bench. It read 13.42V at 10pm and by 5am today it was at 11.73V. I guess that shows the battery is bad.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-1

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-2

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-3

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-4

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-5

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-6

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-7

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-8

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-9

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
Old Oct 15, 2006 | 12:43 PM
  #9  
ZeeOSix's Avatar
ZeeOSix
Le Mans Master
20 Year Member
 
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Default

Originally Posted by TAC
I charged the Optima most the day yesterday on the bench. It read 13.42V at 10pm and by 5am today it was at 11.73V. I guess that shows the battery is bad.
Yes, it's bad. I went through that fiasco too. Do a search on the other site for Optima battery and you'll find many threads of my Optima battery testing results. Also there is info on how to read the date code that’s burned into the batteries.

I had two Optimas that were bad and got both replaced under warranty. At lest Optima has a decent warranty on them.
Reply
Old Oct 15, 2006 | 08:39 PM
  #10  
zalama's Avatar
zalama
3rd Gear
 
Joined: Nov 2005
Posts: 3
Likes: 0
Default

Great discussion here!
So, I have -99 C5.
I have second optima battery now in 9 months, first yellow lasted 2 months.
Now after sitting the car about 1 week my present red optima is all dead.
I checked my battery drainage too:
After the alarm goes on its's 4 amp for few seconds, drops down to 0.8 amps. My only concern is why it only drops down to 0.2 amp(200 mA). I have removed all the fuses and it's still 0.2 A.

This will drain my model 75/25 red optima battery as calculeted :
44 A/0.2 Ah= 220hours=9.1 days.
(Anyway I think the cranking ability is reduced a lot before all the charge is gone)

PS.
I just realized how low AMP/hours this optima battery has.
I'm used to see 60A/h on most cars.

Anyway I think I need to get third battery?!
Reply
Old Oct 15, 2006 | 09:15 PM
  #11  
ZeeOSix's Avatar
ZeeOSix
Le Mans Master
20 Year Member
 
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Default

Originally Posted by zalama
Great discussion here!
I checked my battery drainage too:
After the alarm goes on its's 4 amp for few seconds, drops down to 0.8 amps. My only concern is why it only drops down to 0.2 amp (200 mA). I have removed all the fuses and it's still 0.2 A.
I'd have to dig my notes out, but if I remember correctly the battery current draw wasn't as high as 200 mA when the stock alarm was on. You say 0.8 amp and then 0.2 amps. Kind of confused ... which one is it?

Maybe you have an after market alarm?

Update -- found my thread on the other site. Look at post #4, Item C):
http://www.z06vette.com/forums/showthread.php?t=69875

"C) I set the alarm and after about 10 minutes the current draw on the battery went all the way down to the same 18 mA (key out of ignition) level. Apparently, once the alarm is set the computer must go to sleep, but has the ability to sense if there is any current draw on the system, which would then wake it up and set off the alarm. So, arming the alarm in the garage will not cause more drain on the battery ... something I wouldn't have expected, but good to know."

Last edited by ZeeOSix; Oct 15, 2006 at 09:29 PM.
Reply
Old Oct 15, 2006 | 09:15 PM
  #12  
erick_e's Avatar
erick_e
Melting Slicks
Supporting Lifetime
15 Year Member
Veteran: Army
 
Joined: Aug 2006
Posts: 2,475
Likes: 97
From: KY/TN
St. Jude Donor '13-'14-'15-'16
Default

My redtop will drop to 11.7 a few hours after sitting, and down to 10.1 after a day or two. The car reads 14.1 while charging.

After reading this thread, I finally decided to check for parasitic loss.

I came up with 1.5A immediately, and stayed there. I decided to double check it again and then it measured 1.5A and after a few seconds it dropped to .8A then a few seconds later it dropped to .01A

What relay is it that I hear when I connect the multimeter leads? It is located in the right front somewhere. Is it possible that this relay is sticking and allowing a circuit to stay closed, or is my redtop about to die?
Reply
Old Oct 15, 2006 | 09:26 PM
  #13  
ZeeOSix's Avatar
ZeeOSix
Le Mans Master
20 Year Member
 
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Default

Originally Posted by erick_e
What relay is it that I hear when I connect the multimeter leads? It is located in the right front somewhere. Is it possible that this relay is sticking and allowing a circuit to stay closed, or is my redtop about to die?
If you read this thread carefully, you will see that it takes 15 to 20 minutes for all the computers to "go to sleep" before the battery draw drops to the normal 20 mA or less. Read my link a few posts above.

If after say 30 minutes the current draw is still much higher than this, then there is definitely a problem.

Optima Redtops are notorious for going bad ... so if the parasitic current draw is normal it has to be the battery.
Reply
Old Oct 15, 2006 | 10:23 PM
  #14  
zalama's Avatar
zalama
3rd Gear
 
Joined: Nov 2005
Posts: 3
Likes: 0
Default

Sorry about confusing info. So when alarm goes on, amps jump very quickly to over 10 amps(Can't really see exact value with digital meter) and then drops to about 0.8, then after few seconds, drop to 0.2 amps.
I waited few minutes and it stays at 0.2 Amps. I guess I need to wait little longer.

I allso hear "click" somewhere from head light motor everytime battery is connected, and amps flash to 4.0 and go soon back 0.2 amps.
This sound is not the light motor because I removed light connectors and still hear that click.
There must be something under the headlight. (horn?)
Reply
Old Oct 16, 2006 | 03:53 PM
  #15  
ZeeOSix's Avatar
ZeeOSix
Le Mans Master
20 Year Member
 
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Default

Originally Posted by zalama
Sorry about confusing info. So when alarm goes on, amps jump very quickly to over 10 amps(Can't really see exact value with digital meter) and then drops to about 0.8, then after few seconds, drop to 0.2 amps.
I waited few minutes and it stays at 0.2 Amps. I guess I need to wait little longer.
Yes, wait about 20 minutes and see if the current draw goes down to about 20 mA (0.020 amps).
Reply
Old Oct 16, 2006 | 04:01 PM
  #16  
QKSLVRZ's Avatar
QKSLVRZ
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2001
Posts: 983
Likes: 23
From: Northeast Ohio
Default

TAC,
There's an easy way to measure your current on the 400 ma scale.

So once you're disconnected the battery, and have the meter hooked up, turn the car on, wait until the current drops, then short the 2 leads on the meter out (so power doesn't go off), with the meter shorted, switch to 400 ma, then unshort the meter, it's on 400 ma scale, and the power never got disconnected so the alarm doesn't cycle.

BTW, my car ran right about 18ma.

Oh, down't forget your radar detectors don't shut off.

And remember current meters go in series, and you can short them, Volt meters go across the voltage, and shorting the leads would be a bad thing.
Reply
Old Oct 17, 2006 | 02:52 PM
  #17  
TAC's Avatar
TAC
Thread Starter
Drifting
20 Year Member
 
Joined: May 2000
Posts: 1,797
Likes: 0
From: Thompson Falls MT
Default

Originally Posted by QKSLVRZ
TAC,
There's an easy way to measure your current on the 400 ma scale.

So once you're disconnected the battery, and have the meter hooked up, turn the car on, wait until the current drops, then short the 2 leads on the meter out (so power doesn't go off), with the meter shorted, switch to 400 ma, then unshort the meter, it's on 400 ma scale, and the power never got disconnected so the alarm doesn't cycle.

BTW, my car ran right about 18ma.

Oh, down't forget your radar detectors don't shut off.

And remember current meters go in series, and you can short them, Volt meters go across the voltage, and shorting the leads would be a bad thing.
Being an electrical neophyte I have no idea how to short the meter. I wondered how people got their meter on the 400a setting without blowing the 2A fuse on that setting. In order to do my experiement I actually taped a wire to the negative cable and taped the other end to my probe. I then clamped the other lead to the negative post (Optima-has both side and top connections).

I was going to try simply attaching the negative cable back to the battery with my meter probes intact, retaining power in it's current condition (no pun intended). Then I could move the lead to the 400mA port and switch the meter to the 400mA setting and then remove the negative cable back out of the battery. I chickened out, figuring I would blow up something.
Reply

Get notified of new replies

To Testing for battery drain





All times are GMT -4. The time now is 06:05 PM.

story-0
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-1
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-2
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-3
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-4
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-5
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-6
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-7
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-8
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-9
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE