I agree...SVR Batteries are sweet!
Also I would say that from the symptoms you described it sounds to be an alternator. Can you reproduce these symptopms. If so I would try to do so, and which doing this and the car running, unplug the neg. side of the battery. If you start having problems, then its probably your alternator. If not then you might need a higher rated battery. But I my guess would be that its your alternator, since they have so much going on in the car it might not be charging the battery.
I hope this helps, sounds like you have some work ahead of you.
Peace
Originally posted by KnuKonceptz:
With your battery going dead is a sign of a drain even when the car is off. Now are the inverters on all the time or only when the car is on. If they are on and have to be on you will need some extra batteries. Since all this is in a Contour I am sure it is mostly in the trunk. If you need some small batteries check www.svrbatteries.com the 33-12 and 28-12 are quite small.
When the car is running with nothing on what is your voltage at idle (at the battery and also check at the location that the inverters are getting voltage to see what kind of loss you have), now turn on everything that you have added to the car, what is the voltage now. Finally turn on the cars lights, heater/blower motor and the rear window defrost along with the components you have added.
With nothing on and the car running at idle you should be around 14.4V. Turning on the cars accessories will drop you down to low 13's (worst case) but the car should be able to hold or raise the voltage at idle. Now when you turn on the added equipment, if the voltage is below 12V you will need an alternator that puts out more amps at low rpms. If you raise the rpms and the voltage rises then this supports my last statement. If it does not help you will need a much bigger alternator with possibly an external/adjustable voltage regulator. let me know the results, sounds like a pretty cool car. Have any pics? I have added an inverter to myine as well for my Dreamcast. I was going to add a PC but had to much engine noise from the inverter when attached to the PC (I was going to use the pc for MP3s and DVD)