Rep Power: 259

Hi Everyone,

I have a 2003 civic with a sound system in it. 10'' sub 2 amps one capacitor,
etc...

I just purchased a new Odyssey battery and I was wondering, is it normal that when the car is not running the battery voltage is at 12.35 volts?

when its running its charging at 14.5 volts.

Something that I have noticed is that when I unplug the powercable going to the sound system from the battery the battery voltage goes up to 12.45

is this normal?

can someone help.

 
Rep Power: 453

yes that is normal. when the car is running the alternator is charging the battery. when the car is off nothing is charging the battery.

 
Rep Power: 0

I second that!

 
Rep Power: 263

12.35 on a new battery seems low. I also wonder if something might not be correct with the cap, it may not be charging up all the way if you get that kind of a jump on the battery voltage when unhooking power for your system. What gauge power wiring are you using for the amplifiers? The higher voltage when alternator is on is normal.

 
Rep Power: 259

Well I disconnected the Fuse that feeds the cap, the sub and the Amps from under the hood.

So no power is going there. All the wires that I have are 4 and 8 guage.
I guess it's not the sound system that is doing that.
i also have a compustar and an led light but I am not sure if they draw that much juice.

Man this is like trying to find a needle in a haystack.

I don't know what to do anymore.

 
Rep Power: 453

I dont see what your problem is?

everything is running fine.

 
Rep Power: 259

Well i was just concerned that when the car is not on and just sitting the battery is getting drained.

 
Rep Power: 263

You'll need to do current drain testing if you want to find out for sure if you're having an issue. You need to have a somewhat decent quality meter that does DC current. Any drain over 30-40mA with vehicle off is too much.

 
Rep Power: 259

Well I finally figured out what the problem is. Seems that my compustar alarm system was drawing too much amperage 80 mA. Faulty module.
after i diconnected it had very little draw from the battery. Not sure how these modules go bad on you but he at least the problem has been solved.