I thought I was able to avoid this thread but for the first time yesterday mine didn't start. Car sat for 11 days and and it would only click. Car has sat in the past for as much as 3 1/2 weeks.

 

I would follow Charlie (metroplex's recommendation, and have the smart junction box tested.

Just my $.02

 

Just to add a little info, the last time I had to jump mine off, the radio presets were still stored even though the battery was completely dead. (stereo was left on)

EDIT: Just checked and my Active Anti-Theft came with the BXT-40R battery.

 

My car dies within 4-5 days if I lock it with the keyfob.

I just returned from a 10 day vacation a few days ago. Before I left, I disconnected the negative terminal on my battery. When I reconnected it and started her up after 10 days, it took about 2-3 seconds (instead of 0.5 seconds) to start the engine.. guessing because my battery was low after 10 days, even while disconnected.

I park my car at a friend's parent's house that happens to be very close to the airport, so battery tender / jumping / etc, is not really an option. I just disconnect the battery to be safe.

 

OMG... that Carputer install is the shiznit. That blows away SYNC by light-years.

 

I've now read in a few places that others also suspect that the Shaker's (500 or 1000) bass amps stays on if you turn the car off with the radio left on. I now recall doing that before the last time I drove it! I think you may be on to something here VA Stang. If what I read elsewhere is correct and it's the amps (external to the radio head unit) a head replacement would not fix it - all seems to start to make sense.

So for me it's 'Turn off the radio first, then the ignition' for a while and see it that's it - I hope so. Thank's VA Stang, your comments fit the facts in my case.

 

Just for the record, I've always turned the shaker 500 off, before shutting down the ignition. And yet my car still died within 7-10 days. But since I've been using a battery tender, I haven't experienced any battery problems in over 2 years.

That being said, I would follow Charlie (metroplex's) recommendation, and have the Smart Junction Box tested. Perhaps that may be the reason behind batteries discharging !

 

Thought I would reply to this thread instead of making a new one.. Anyway..

Having the same problem. 2005 GT, not my daily driver. Battery started dying after about a week (sometimes could go longer) of no driving. Eventually I got fed up with jumping it all the time and replaced it with an optima red top battery. It was fine for about 4-5months until this morning.

Has this been investigated any further?

 

I had this problem early on but have discovered that since I disconnected my Shaker 500 amps and went to an aftermarket amp and when I park it in the garage I do not arm the alarm, and turn everything off (AC, radio, radar detector, unplug Ipod, unplug phone charger) I haven't had a problem at all.

 

I was trying to remember to turn the stereo off everytime I parked it but I think I left it on this time thinking that the optima battery would hold a charge over a week.

 

Optima batteries have less capacity than their flooded lead acid counterparts. I am not sure where people got the idea the Optimas are superior batteries overall. In vibration intensive or high heat environments, I'd say the Optimas have the edge. In terms of life-span, capacity, and bang for the buck, flooded lead acid batteries FTW.

 

You're in the minority.

 

Knock on wood *tapping knuckles against the side of my head*, I haven't had a dead battery yet. I have left our Mustang in the garage without starting it for a couple of weeks at a time without turning off the radio (Shaker 500). Thanks to this thread I am now turning it off. Sorry to hear some of you are having this problem.

 

I see that, but I now keep a battery maintainer if I intend to store the car. This is good practice on any car that gets rarely used.

 

Just thought I would bump this up.

I am 100% certain that the current draw is from the Shaker 500 Amp (1000 too?) or something in the head unit.

I have had the car parked for a month with the radio off and it still fires up fine. Leave the stereo on and I'm lucky to get it started after 5-7 days.

It's suprising there was never a recall on this.

DM

 

I had a dead battery problem myself. Found out the P.I.E. Ipod adapter was improperly installed. And cost me $160 from Ford for labor just to identify the problem, and still not fix it.

I had it die once before after it had been sitting all weekend during the middle of winter. I had it jump started, and Ford replaced the battery for free since it was under warranty. But it got to the point where if it sat for 1 day, the battery would die. So I took it into Ford, and they did some tests on it. They found that the 1 month old battery was completely dead, but saw nothing draining the power. And it died again. Took the battery to Autozone. They tested, and recharged the battery, and saw no problems. They asked to have the car brought in, and they would see if there was a drain. Nothing was noticed.

It died again, so this time I was fed up. I took it to Ford, and told them. There is something wrong. I need to know what it is. So they kept the car for a day. Tore it all apart, and did some other kind of test, which showed that the ipod adapter, (which had an extra wire attached to something it shouldn't be attached to) was drawing X amount. They gave me a full report, left the car all torn up, and gave me a bill for $160. So I took it back to the place that installed the unit, and they swore up and down that it was not their problem. They ran their own tests and they showed nothing was wrong. I gave them the report that Ford gave me, and they said that they would just swap out the unit.

It hasn't died since.

 

So I finally became a victim of this issue. Talked with my service advisor and he has also had the issues since he does not drive his car a lot either. What he did was to step up to the Motorcraft 850 CCA battery and remove some of the material from his battery tray to accommodate the larger battery and has not had the problem again. He has also suggested this to a few customers to solve the same issue.

 

kinda makes sense.

 

Here is the Motorcraft part # BXT 65 850

 

That's a Group 65 battery, the same one used in the E-series cargo van and the Crown Victoria. That is a rather large and heavy battery. If you do plan to upgrade to a Group 65 (which BTW can go up to 1000 CA), I recommend a trunk mounting to prevent it from messing up the weight distribution.

FYI, I have not driven my 07 GT for about 3 weeks and the battery voltage is at 12.70-12.79 VDC at 65F ambient. I am using the stock battery.