My wife has an '07 Mustang. We left town for a month and left her car parked in the garage. Upon getting home recently I found the battery to be dead. When I opened the hood to charge it, the positive battery terminal was covered with a mass of blue corrosion. Everything was fine when we left, any ideas what would cause the corrosion in one month's time? :confused:

Cracked battery or bad seal around the battery post leaked acid onto the terminal. Replace the battery, and the cable too if it doesn't clean up.

When I opened the hood to charge it, the positive battery terminal was covered with a mass of blue corrosion. Everything was fine when we left, any ideas what would cause the corrosion in one month's time? :confused:
Are you 100% sure the corrosion wasn't there before you left? Most of the time mass corrosion is caused by overcharging, high charging rate for long periods or what pnugene said.

My wife has an '07 Mustang. We left town for a month and left her car parked in the garage. Upon getting home recently I found the battery to be dead.
Newer cars have a larger electrical draw when sitting than the older cars do. Even the owners manual says to disconnect battery if going to be left sitting more than a month (GM cars). Personally I would disconnect the battery or buy a battery maintainer, like one of these.

http://batterytender.com/default.php?cPath=11_3
http://batterytender.com/default.php?cPath=11_2

Not 100% sure none of the corrosion existed before it was parked, but I never noticed it.

My wife's 05 Mustang sits quite a bit (5000 miles on it since it was new). Sitting like it does, the battery has ended up several times. It's always taken a charge and come back to life. This is the current draw that was described.

It's never gotten a bloom of corrosion on the terminals. I'd say clean it up, use some battery washers and a little grease. Watch it closely and if it doesn't come back, your good to go.

The 05 and up Mustangs seem to have this as a known problem, apparently due to the amount of stuff that is alive when the car is off. Go to Stangnet or IMBOC and do a search. My 08 Bullitt has sat for just over a week at the airport a couple times with no prob. The feedback I see is that if you jump/crank it and charge it, it will go back to work with no problem.

I don't remember, but there may be a tsb or a fix out for it.