Got the same problem here, did a voltage check after a full 24 hr charge, it was only charged 75%, been driving the car a lot, re-cecked, same 75%...Alternator is checking out good.
Interesting enough is that last year ( winter 2005), I left the battery hooked up the whole 3 months with no startups at all, went to start it in the spring, fired right up!!!
Had a similar issue when I first got the car, the dealer told me it was my radar detector, and if I was going to let it sit more than 3 days, to shut it off.
So my car sat for about a week and a half while I was installing the silverhorse louvers, went to start it...DEAD! Even got the window low power syndrome of no auto up, so I charged it overnight, reset the windows per owners manual, then read the battery at 75% charged.
I guess it is time to see the dealer...I DREAD IT!!!!

 

i've been doing some testing with an Amp meter. I'll post all my results up soon. So eveyone we'll have something to take to the dealer and give them a better idea of how to deal with it.

In short...
I wanted to test the Radio OFF theory before turning the key to OFF.
I have only tested the my car for about 8 hours (continuous) so far and i can tell you for certain that the leaving the Radio ON or OFF before turning off your car has no affect within an 8 hour period after you leave your car.

However Turning the Radio OFF over several days does seem to keep the battery from draining. But im still testing this to find out at what point the Radio actually starts draining. I know it's after 8 hours after turning off the car, but when exactly?? I will find out soon.

I will have a chart for you with almost min by min play on the current load.

From my findings so far, its now understandable why Ford hasn't yet detected the problem or why numerous trips by people here have yielded no fixes from Dealerships either.
Because when the Dealership does this battery checks, etc, its only for a few hours at best. And all they do is check the battery load and some other electrical stuff.

But now i know this issue activates some time after 8 hours.

Anyway, i'll be posting the results soon. just have to find time to do the 8+ hours (days) testing.

 

Best thing I can recommend Nick is to make a unit that goe's between the positive battery terminal and the positive battery cable that will allow you to slowly drop the voltage to check on the shaker 500 to see if it starts to cycle looking for cd's .

 

What the heck – me too!

I go away for 8 days – and I find my 06 GT to be dead – as in not even a glow from the glove box light dead.

My car never hinted at any battery / electrical / charging issues so – wth?

So I search around and find this is not uncommon ….
Hummm

Very informative.
(Thanks to all the previous posters for all the great work / insight.)

Thought I’d put in my two cents worth.
As I mentioned, my car never hinted at any problems.
During the bleak cold California winter (dang – I think it got down to the low 40’s!), I parked my car for an extended period of time – I’d say some two months with no problem. (BTW - My car has the factory optional alarm the Anti-Theft version, which I gather draws a bit of power).
I simply locked it (with remote) setting the alarm and walked away – no problem.

So – yes – I was really surprised when I found my car dead after only about a week.

SO – knowing nothing of the possible problem – I do remember something I thought odd at the time I started the car up.

I pulled another car around to jump start the Mustang – and sat inside as my son connected the cables.

I remember sitting there, driver door open – and seconds after the cables were hooked up – the dome light was just beginning to glow – and the CD changer stared to change / seek incessantly. I remember thinking what’s up with that?
I didn’t stop on its own – just a constant shuffle of the CD changer.
Weird no?

I’m pretty sure I had to turn on the radio in order for the shuffling to stop.
Just thought this might help in figuring out what’s going on.

 

My 05 lost its battery a few months ago. I took the battery to ford and they replaced with a Motorcraft and billed it as a warranty item. Didnt cost me a cent but my time.

 

I just had the exact same thing happen to me on Saturday, cleaned the interior of the car with the stereo on, took maybe 15-20 minutes tops, went to start car and nothing. Unfortunately I had to be on the road in the next 30 minutes so I just had to have a friend drive me to get a new battery and not deal with it then.

Think there is any chance Ford will reimburse? and should I still take it in to have it looked at so it doesnt happen again?

 

I am glad I still poke around here. I searched for louvers and found this thread?????

My 05 GT had twice died just sitting in the garage. I know it is bad when I click the key fob and the door does not unlock. This is only after about a week and half of sitting in the garage. I jumped it with a starter box both times and have not had it happen in a few weeks.

 

If it is just sitting in the garage, you should lock the pass. door by hand, and then lock the driver side by turning the key in the door lock cylinder. This will activate the alarm but without the motion sensors (this only applies if you have the active anti-theft). This should help keep your battery going for a long time.

 

wouldn't just clicking the key fob ONCE instead of twice do the same thing? (lock the doors but not arm the security system) just so you can check to see if thats what is draining the battery? just a thought

 

Mine just died (completely) for the 3rd time. I've been trying to maintain the battery with a trickle charger once a week if the car doesn't get driven. Car is parked in the garage without the active alarm set and the radio off. I was just gone for a week - trickled the battery before I left and it was dead (resting voltage of 5V - obviously the battery is shot) when I got back. I had the dealer replace the battery today - we'll see how this new one holds up...

 

Clearly these batteries are crap and this is a perfect example of how Ford gets in trouble with customer perception. This is NOT a Ford manufactured product BUT in many customer minds, these crappy batteries ARE Ford. They should be going back to the supplier and demanding a recall on these things. We're all going to need new batteries and we'll end up paying for them. Mine has died twice, and according to this thread, we should begin something to contact Ford over these POS batteries. Why should we all spend $75-$85 because their supplier made a crap product?

 

The Batteries are covered under warranty, I've had 2 of them replaced without having to pay a single dime..and BTW, it's not just the batteries ? it's also the incline motion sensor, which is part of the active alarm system, that's mostly responsible for draining them, in the first place..Instead of using the keyfob to activate the alarm ? I just use the key, which activates the alarm, for just the doors, trunk and windows, but not for the incline motion sensor..After letting the car sit for up to 30 days, in the garage ? no more dead battery..I strongly recommend giving that a shot, and see if that doesn't solve the problem first

 

NO ! all it takes, is just one click to activate the alarm and security system..Using the key, is the only way to prevent arming the security motion sensors.

 

Correct. Clicking it twice just confirms the alarm is active by honking the horn. It goes active with just one click on the lock button on the keyfob, or by hitting the lock switch on the door panel prior to exiting the vehicle.

Putting the key in the door and turning it to lock the door from the outside only arms the door/trunk/hood sensors...and not the incline or motion sensors.

 

The 07s don't even have a glove box light.

 

I misspoke I meant the dome light.
I don’t have a glove box light either.

The point I was trying to make is that the CD changer was on as soon as I hooked up jumper cables.
The first thing I notice as the cables were hooked up is the CD changer shuffling.

So – as per previous posts – I make sure I set the Shaker 500 unit to a radio station – and then turn off the radio – before turning off the car. No more turning off the car with the CD player going. Doing this little routine seems to cure the issue.

 

Went out to start the stang tonight, she was dead. No headlights (nothing)
Being the battery is only 33 months old, I figured it may be more than a battery. Went over to Sears and sure enough they detect a leak in electrical system. They told me to pop the trunk, so they could see if the trunk light is staying on. I removed that light bulb months ago(due to open trunks at car shows). I started moving the harness around for trunk lid light and the problem goes away and comes back. Looks like I will be taking her to dealership next week. I hope the stang starts tomorrow.

 

All, I’ve had the battery die a number of times too. I’ve since bought a battery tender to keep the battery charged while I’m out of town but I hate the fact that this is the answer. The dealer was no help, no big surprise their but it irritates me when they say that if I had an ESP (extended service plan) they’d be happy to keep my car for days on end to find the problem and provide me with a rental... What good is the warranty’s that comes with these cars? (Rhetorical)

Ok so I have found the official Ford step by step for testing battery drains. My apologies if this has been posted before but I’m fairly sure it has not. I’m not sure I will get to testing this until the fall as my garage temps are hovering around 103 degrees during the day. But wanted to share just in case someone else with a bit more expertise than I might find this useful. And of course if you do would you post your findings... Thanks again to a fantastic mustang community.

 

Chaulk me up to the dead battery club.

Went away for 3 solid days and when I went to start her up, dead. I'll be taking her to the dealer a lunchtime. I have a Shaker 500, and I did have the alarm on while I was away.

 

Your 103 degree garage temperature might have something to do with your battery having reduced life than average:

http://www.batterystuff.com/tutorial_battery.html#8