The cap and battery are in a parallel circuit. The voltage in all parts of that circuit will be the same or very close. If your battery is stuck down at 10.8 volts (dead) then the cap will be at 10.8 volts as well.

If anything, a capacitor should generally always sit slightly lower than battery voltage, due to the loss in the power cable from the battery to the cap.

It sounds like you have to jump your battery often. Time for a new battery.

 

I have a 6 month old Red Top, its not my battery that does it, its from leaving my lights on, or the odd time my interior lights wont go off.

 

I agree. A new battery indeed...

 

Ummm....... Wow...

No. Bad.

http://www.allstart.net/batadv.htm