I had the issue last year, 5-7 days of sitting is was real slow to crank, just barely started a few times. So I got a new Interstate. Was fine.
Then Winter came, sat 2 weeks was fine, used it on a nice day. Parked for 3-4 days before putting away for winter and it was stone dead. Charged it by running it for about an hour, driving around. Brought it into the heated shop, washed it, left it there over night, 10 hours later in a warm shop was dead again.
Jumped it, let it warm up, took it on the 15 min ride to storage garage, covered it and left it to die until Spring. Ill warranty that Interstate when I take it out, but I think it was more of a car issue draining it.

 

I had let my motocrap battery sit for 2 weeks at at time no problem.

Then, last october it died on me. Wasn't too pleased, but i guess i was on borrowed time.

 

Welcome to the f'n dead battery club. Mine died after 3.5 years.
Replace it with a better one! (anything other than a neverstart')
You likely wont have any problems with a new battery.

 

those whose batteries died-
Was it sudden? I mean had you noticed it getting weak and then one day just be dead?

Or did it become harder to start, which could give you a clue that it might be going bad?

Mine's almost 4 years old (in April) and I've never had a problem with the stock battery. Will it just fail one day or could I expect some signs of trouble first?

 

I guess i'll call mine sudden. Although i was only starting it once a week at best over the last couple of months. But until Sunday night, I had never even had what you might call a weak start. Which is why this death confused me so much. In fact, walking up to the car i just thought the remote battery had died when it wouldn't unlock.

Pre-november, when it was my daily driver, i never had any issue. So i guess there is something to that "start it every day" thing.

 

Looking back, yeah, I noticed that it was sluggish to start (even more than normal for a cold morning). Seems that it was on a downward spiral for a few weeks and then bought the farm.

My Z-28 sits in the garage for the winter (13 winters now and I believe it is only on its second battery...possible third, but I lost track). Once in a while (on decent winter days), I'll take it out for a quick spin. That car starts up like a champ...even when it has been sitting for weeks.

 

ALL lead-acid batteries are prone to catastrophic failure simply by the design of the plates. It's not uncommon for a deteriorated plate or 2 or 3 to fail while driving and you'll never be aware of it (since the alternator is supplying the electrical loads) until you shutdown and go to restart. Some batteries fail sooner than others and like most things in life, I'm sure Ford went with the lowest bidder to make these batteries under the Motorcraft label.

Since we're aware of it, we need to be proactive and those that suspect their battery is on the verge should not wait and attempt to replace it ASAP. You'll have to do it sooner or later so why wait until the "always-inconvenient" time it goes south.

 

Mine died due to the alternator failing...while I was driving. Free tow, alternator and battery replaced under warranty.

 

mine died not long after i got it and i did the same thing got a jump from roadside assistance then went straight to the store to buy a new battery

 

I am confident the Shaker in combo with a crappy battery is to blame for all battery related problems in the s197 mustang.

My shaker killed my battery after sitting for long periods of time (1 week or more). After I changed to an Alpine radio this problem went away.

I just changed my 3 year old battery with a Red Top and all is good.