V8Mike

Maybe noobish, maybe not, I don't know.

I went to replace my battery on my 05 GT this weekend. It was giving me trouble on cold starts and was dead a few times after leaving it for a few days. About 45k miles, so I figured a new battery was in order.

I go and pick up a Die Hard Gold at Sears, the recommended size. When I get home I was chagrined to discover that the battery they sold me was a good 2 inches longer and 1 inch wider than my factory Motorcraft battery. So I was irritated, and took the battery back.

So I go over to Pep Boys, now with my Motorcraft battery in hand, and check out their selection. Their recommended size Bosch is similarly larger than my factory battery. The heat blanket won't fit around it and it doesn't fit the battery tray without somehow modifying the tray. So clearly my factory battery is smaller than what is 'supposed' to be in there.

Did Ford put some sub-standard battery in my car from the factory? The one in my car states '500 CCA' and the recommendation is 590CCA minimum. I'll have to post the model # later on when I get home.

m05fastbackGT

Mike, is your Motorcraft battery BXT 96-R. ? If it is, Then I recommend you upgrade to Motorcraft battery BXT 40-R. Which has 590 CCA, and is designed for the 05-09 Mustang.


Hope this helps.




-Rocky

Glenn

do you plan on keeping your car more than a few more years?

karman

I thought it was a BTX 40R.
This might work too:
http://forums.bradbarnett.net/showpo...7&postcount=19
http://www.autozone.com/R,209308/ini...ductDetail.htm
Same manufacturer, Johnson controls.

m05fastbackGT

Your correct, it's a BXT 40-R. I must have misread it, while looking it up on my battery for V8Mike.

At any rate, It's now been corrected. In the meantime, thanks for the heads up.

V8Mike

Yes.

V8Mike

It was the 96-R. I replaced it with the Duralast 47-DL. Seems to work better than before. Did Ford just stick a substandard battery in the 05's?

metroplex

My 07 GT came with a BXT-96R even though it has the active alarm system and Shaker 500.

m05fastbackGT

I'll put it this way Mike, IMO Ford should've installed the Mustang with the BXT 40R battery, as it indeed does have 590 CCA.

metroplex

Both the 96R and 40R were designed for FWD cars like the Mazda6. My Crown Vic has a Group 65, with up to 1000CCA. However you want to look at Ampere-hours for capacity.

Glenn

optima red top would be my choice I think

m05fastbackGT

Charlie, would a Group 65 fit in a 05-09 Mustang, and also be compatible

metroplex

Unfortunately, not without some major changes. The 65 is significantly larger than a 40R or 96R (about twice the size). The 65 is also used in the E-250/E-350 cargo vans so it's not a small battery. I think Ford chose a smaller battery for the Mustang to reduce overall weight and they placed it at the firewall for better weight distribution.

You could install a 65 (or 2) in the trunk with a custom tray and longer wiring, that would improve the weight distribution and get the battery out of the hot engine compartment.

m05fastbackGT

I suppose that's always an option, good point indeed