C6 battery drain riddle. Please help!
Racer
Joined: Aug 2008
Posts: 413
Likes: 22
From: Justin TX
I have not measured the battery draw on my 08 at rest, but .47 amps may not be too far off. That is only around 6 watts, .47 x 12.6 = 5.92 watts.
Based on this link 6 watts on an 700 amp hour battery will last 583 hours or 24 days.
http://ep.yimg.com/ty/cdn/sports-imp...drainCalc.html
I understand that is about right if you store your car and do not have it on a tender. From what information I have found if the car is going to be parked for more than 4 days, put it on a tender.
I will try to test the draw on mine just to see what it is.
Based on this link 6 watts on an 700 amp hour battery will last 583 hours or 24 days.
http://ep.yimg.com/ty/cdn/sports-imp...drainCalc.html
I understand that is about right if you store your car and do not have it on a tender. From what information I have found if the car is going to be parked for more than 4 days, put it on a tender.
I will try to test the draw on mine just to see what it is.
Racer
Joined: Aug 2008
Posts: 413
Likes: 22
From: Justin TX
Mine was reading more than 12 volts with my Fluke 87 meter. With the hydrometer 4 cells were floating 4 or 5 ***** and 2 were only floating 2 or 3. New battery, no more problems in over a year.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
Testing a battery with a volt meter is not a good test because a meter provides no load for the battery to work against. The battery must be heavily loaded and then checked for voltage while it is working hard against that load. The battery must be tested under the same conditions that it is used...under a heavy load that simulates the starter motor.
Pro
Joined: Nov 2001
Posts: 569
Likes: 23
From: Venice Florida
Testing a battery with a volt meter is not a good test because a meter provides no load for the battery to work against. The battery must be heavily loaded and then checked for voltage while it is working hard against that load. The battery must be tested under the same conditions that it is used...under a heavy load that simulates the starter motor.
Make sure to use the CCA when determining the amp load. CCA is rated at 0 degrees F. Some manufactures market the Cranking Amps (CA) which is rated at 32 degrees F which makes the battery appear more powerful than it really is.
Hydrometers are a good tool to use in conjunction with the load test. After charging, all cells should be within 30 points or less. 1250 to 1260 on hydrometer would be fully charged. Example: 5 cells are at 1250 and one is at 1210 = bad battery.
Racer
Joined: Apr 2003
Posts: 337
Likes: 0
From: Boothwyn P.A.
how can you disconnect the onstar so it wont draw? mine is not active, thanks!
Intermediate
Joined: Oct 2015
Posts: 29
Likes: 6
From: Phoenix AZ
I have not measured the battery draw on my 08 at rest, but .47 amps may not be too far off. That is only around 6 watts, .47 x 12.6 = 5.92 watts.
Based on this link 6 watts on an 700 amp hour battery will last 583 hours or 24 days.
http://ep.yimg.com/ty/cdn/sports-imp...drainCalc.html
I understand that is about right if you store your car and do not have it on a tender. From what information I have found if the car is going to be parked for more than 4 days, put it on a tender.
I will try to test the draw on mine just to see what it is.
Based on this link 6 watts on an 700 amp hour battery will last 583 hours or 24 days.
http://ep.yimg.com/ty/cdn/sports-imp...drainCalc.html
I understand that is about right if you store your car and do not have it on a tender. From what information I have found if the car is going to be parked for more than 4 days, put it on a tender.
I will try to test the draw on mine just to see what it is.
Reserve capacity is defined as how many minutes the battery can deliver 25 amps before the voltage drops to 10.5 volts.
The battery on my C5 has a reserve capacity of 110. So this is:
25amps X 110min/60(min/hr) = 45.83 Amp-Hour.
Then 45.83 Amp-Hour/.47 Amp = 97.5 hours or 97.5/24 = 4.06 days
I also have a battery drain issue on my C5. The drain is 0.25 amps and should be about 0.02 amps.
