What is the proper voltage for a battery at rest?

[fumanchu182]

Drove the car Sunday and parked it in the garage. Don’t think I left a light on inside or anything else. Wednesday morning battery is dead, not even enough to open the trunk. One jump pack later, got the trunk open and had to jump it with the RAM. I drove it today for lunch, got home turned it on and off and she’s been on the tender since. Got in and it says 12.0v even. Took the tender off at 1422, if parasitic loss is involved we’ll find out in an hour. Did notice that the Tazer and HP Tuners are active on the bus even if the car is locked. 🤔 Anyone have this happen before?

 

[BULL]

Drove the car Sunday and parked it in the garage. Don’t think I left a light on inside or anything else. Wednesday morning battery is dead, not even enough to open the trunk. One jump pack later, got the trunk open and had to jump it with the RAM. I drove it today for lunch, got home turnes it on and off and shes been on the tender since. Got in and it says 12.0v even. Took the tender off at 1422, if parasitic loss is involved we’ll find out in an hour. Did notice that the Tazer and HP Tuners are active on the bus even if the car is locked. 🤔 Anyone have this happen before?

I believe the number you're looking for is 12.6-12.7, but I think you'll only see that in a completely charged AND disconnected condition.

As for the Tazer, it's supposed to not keep the bus active, but I found it can, and did kill my battery once. But all it took was a full recharge and all was fine. After that, I no longer leave the Tazer connected if I'm not actively using it.

 

[Catless]

Sounds like your devices did not let the CAN bus go to sleep which killed your battery. I had this happen with a Trinity in my 2009 Challenger. I had to change the bus ping time to resolve the issue. However even when properly working and dormant the Trinity drew WAY too much current itself so I never left it plugged in for more than a day.

 

[Whatknot]

12.6 to 12.8 volts.
Under 12.6 is low, under 12.4 is basically dead.

 

[fumanchu182]

Went downstairs, car started no problem. Going to leave tazer and mpvi unplugged till racing.

 

[vortecd]

my light weight battery has a gauge on it and it is normally at 13.2-13.4

 

[vortecd]

If you have the factory battery I would be replacing it. My '16 went this year and yours is a '15. I was playing with the burnbox one day and shut the car off without ending the cool down on it and my battery was dead the next day. As long as they are not running, they will be fine to leave hooked up. Haven't had an issue since

 

[Mike L.]

I keep mine on a trickle charge and check voltage under the hood from time to time while it's charging. The voltage will go up to 13.3V and then shut off till it gets to 12.7V and then turn on again till it gets to 13.3V.

 

[Diboblo]

Tazer eating batteries is a thing.

FYI.

Bob

 

[fumanchu182]

If you have the factory battery I would be replacing it. My '16 went this year and yours is a '15. I was playing with the burnbox one day and shut the car off without ending the cool down on it and my battery was dead the next day. As long as they are not running, they will be fine to leave hooked up. Haven't had an issue since

Yeah already replaced the battery this year, was the original 2015 battery and it had a great life. So far car is good. Not worried at all.

 

[jonx96]

My cars an 18 and it seems the battery is going week. I’m hoping it is good till spring since the season is about over.

 

[Old Mopar Guy]

Burnbox left plugged in killed mine. Recharged and no issues. My '15 is still on its original battery.....so far....

 

[vortecd]

my burnbox is always plugged in. Like I said, you probably left something on. As long as nothing is engaged it will not draw voltage

 

[jonx96]

I haven’t had issue with burnbox with the car off. I have left the car sit for over a week without issue.
only issue I have with the burnbox is the traction control error after the burnout

 

[72 440 Barracuda]

Burnbox left plugged in killed mine. Recharged and no issues. My '15 is still on its original battery.....so far....

I believe the burnbox killed my battery as well - I parked it overnight with the Tazer attached and the battery was dead the next morning. The battery was a new (less than a year old), I recharged it and it still seems good. I now pull the burnbox when I park it for any length of time...

 

[vortecd]

I haven’t had issue with burnbox with the car off. I have left the car sit for over a week without issue.
only issue I have with the burnbox is the traction control error after the burnout

Maybe it is because the burnbox is in the trunk. We talked about this. Before this year I was using it in the dash and never had it do that

 

[72 440 Barracuda]

Mi

Maybe it is because the burnbox is in the trunk. We talked about this. Before this year I was using it in the dash and never had it do that

Mine is in the trunk... never used it under the dash.

 

[vortecd]

Mi

Mine is in the trunk... never used it under the dash.

That was in response to Jon about it changing the screen after the burnout at the track. Last year it was fine under the dash. Since it has been in the trunk after the burnout it goes back to street mode so I have to change back to my race settings before I get to the line
I may move it back to the dash and see if it still does it

 

[Old Mopar Guy]

Mine was mounted under dash.