My 2007 Mustang GT's factory Group 96R battery is on its last leg. Even with the water levels up and fully charged by my tender, I can hear the starter taking a tad longer to start the engine.

My 07 has the factory active anti-theft alarm system, and for some reason I recall I did not get the larger battery. Does anyone know if the Group 40R (or whatever battery they used for the Mustangs with the alarm system/Shaker 1000) will be a direct drop-in replacement for the 96R?

If not the 40R, is there another larger capacity size I can try?

 

I didn't know the active anti-theft/shaker 1000 cars came with a bigger battery. I will have to check mine when I get home to see what mine came equipped with.

Over this past winter I had trouble with mine. I pulled it out and left it on the bench for a week on a trickle charge. It was good after that, but i doubt it will make it through this winter.

 

My Tender has lit the green LED meaning the battery is full charged, but I can still hear the engine taking like a split second longer to start. I used to think it was because the engine might be older now, or the combustion chamber may be "cob-webbed up" since I haven't really driven the car. But I guess it makes sense the battery is on its way out. Although I did keep the Tender on the battery for the entire storage period, and I've never had a factory battery last longer than 3 years.

 

Jim what did you find out?

 

I looked at the specs for 96R and 40R, and there's not a huge flipping difference in capacity or cold cranking amps. I'll just go with another 96R. It looks like the Duralast Gold and Sears DieHard Gold are Johnson Controls batteries, same as the OEM Motorcrap battery.

 

The dealer sells a 96R with 590 cca with more reserve time for those models with active alarm and shakers.

 

I put the interstate 40R in mine
looking at the specs, CCA and CA are both the same
They say the 40R is one of the most powerfull batteries, and listed under heavy duty, and the96R is standard duty, why not sure, but the 40r weighs 3.7 lbs more, lol

 

The 40R isn't one of the largest car batteries. Group 65 is what Ford typically uses on vans, trucks, and large cars. The E-250 (5.4L 2V V8) has a Group 65 and my Crown Vic has a Group 65 - these are about 850-900 CCA / 1000 CA with 72 A-h capacity. The Group 40R/96R is designed for a small car, so I am not sure why Ford used such a small battery for the Mustang.

 

I agree, I was surprised when I looked up the battery for my car that it wasn't a 65 series.

They do run a little bigger, and not sure if reverse terminals are available, so fitment might be an issue?

 

The 65 is pretty big, and I don't see it fitting in the S197 without a new tray and possibly relocating it to the trunk.

 

Many newer model Fords use the 40R & 96R batteries displacing the use of 58 and 65 series batteries.

 

I put a 40R in mine last week.. had 96 option but the battery size was different than what was coming out and while probably wouldn't did not want it sliding around.

http://www.autozone.com/autozone/par...1278_206883_0_

 

Our '08 GT was purchased by us in 2013 and it still had it's OEM Motorcraft which I found a 2008 date code on when I replaced it April 2017. That's 8-9 years … just replaced that April '17 battery with yet another today under it's warranty... as the April '17 Battery was beginning to loose it's charge in like a week or two and be dead.


That OEM Motorcraft was doing better when I removed it due to age alone. Good batteries they are.