I know there are plenty of threads on the battery issues with the 2005's. However mine is a little different. I had to replace the OEM battery about a year ago. Bought a new Optima Red Top and until the past few weeks I have never had any issues. I am running two amps (Remote Delay switches) and Alpine head unit and a Zune plugged into the cigarette lighter. Also, I am running some BBK UDP's. I disconnected the stereo system completely for a week and still after a full charge over night the battery was down to 55%. I had the battery checked at a local store and it was showing 65% charge at that time. I bought a charger, let it charge until 100% just yesterday, and this morning it was dead, down to 50% charge again. Prior to this I pulled the cables from the stereo and amps, disconnected the Zune from the lighter and checked to ensure that everything was off and unplugged. Not sure where else to check unless I start looking at the starter or alternator. But something is draining. I am going to pick up a multi-meter this afternoon and see if anything is drawing from the battery. Any clues?
Well, you turn all the electrical components in the car off and wait 3/4 of an hour. If you are drawing more than 50 milliamperes, then you start pulling fuses until you find the one that indicates the circuit that has too much of a parasitic draw. If the parasitic draw is less than 50 milliamperes, then you probably need a new battery.
Oh yeah and when you check for a draw you have to disconnect your positive cable from the battery and then install the multimeter inline between the positive cable and the battery. It sounds like you have something staying powered up (or as Art161 would say "parasitic draw") causing the excessive drain on the battery. Cars nowadays are smart enough to turn-off the interior lights, but on older cars, an interior light that was left on for 3 - 4 hours, could draw a battery down quickly.
I'm assuming you made that mistake once. A friend of mine is college made that mistake with 110v and fried his meter.
First off i don't like Optima's ( interstate batteries) Read somewhere that the Gel cells dont absorb electricity fast enough to be used in an automotive enviornment. I have 2 amps in my mustang and was draining the battery faster than the car could charge it. I was using an optima "blue Top" I went to an Odyssey 2150 battery and never had a problem again. Odyssesy are AGM deep cycle batteries capabe of being fully drained 200 times and still work fine. (ive totally killed mine at least a dozen times.) They also have no limit on how fast they can be charged. Another issue is that you may have an Alternator thats draining the battery when the car is turned off. (not sure if ford ever fixed that issue) If you do that test as recommended above and you notice a draw....then try disconnecting the alternator and see if theres no draw. When i ran 2 amps and a Optima i was killing my alternator because my optima wasn't keeping up. I also had a 200 amp alternator too "new". Deep Cycles are best for stereo systems. (Don't even think of an Optima deep cycle) Chris
Never made the mistake, well never made the mistake that I can remember. But I guess thats why they sell meters with fuses! Then again, meters are a cheap purchase. I think you can get a pretty decent craftsman model for around $20.
