changing the battery


dr914

GT Owner
Feb 11, 2009
252
Marietta Georgia
no but the interior light was on the whole time, and everything works perfectly and nothing has changed, and the battery never ran flat dead, so think that I am ok. I plugged in the small battery into the lighter before disconnecting the main battery
 

Revans134

GT Owner
Feb 3, 2019
16
Scottsdale
I recently changed my battery to the optima group 25 as well( although I didn’t think of Keeping the sticker!) but I nor Sanderson Ford was able to get the rubber block that held down the original battery (8mm bolt) to grab hold of the smaller lip on the Optima group 25. the Ford GT tech( only one in Arizona) couldn’t get it to hold onto the new battery, ideas???
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
To be safe I would get another 12v lead acid battery and fuse it with 10 amps and plug it into the accessory port. The fuse may be redundant as the accessory port has one as well. This will protect you from things lights coming on by design or accident. If I remember correctly the quiescent current is about 20 to 50 ma and less with the car locked (strange). But open a door hit the brakes, touch a switch then SOL!
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
I always tie a string around the bolt so it does not fall out and you can manipulate it easier. Never had a problem, but make sure the battery itself is seated ALL the way down. You can tell when you try to put the trunk back in. If not seated correctly, the liner will not fall into place.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
I recently changed my battery to the optima group 25 as well( although I didn’t think of Keeping the sticker!) but I nor Sanderson Ford was able to get the rubber block that held down the original battery (8mm bolt) to grab hold of the smaller lip on the Optima group 25. the Ford GT tech( only one in Arizona) couldn’t get it to hold onto the new battery, ideas???

There shouldn't be any problem to do this. Make sure the battery is all the way forward and make sure the "foot" a the end of the long bolt is on correctly. We've done dozens of replacements and always get them clamped in well.
 

Revans134

GT Owner
Feb 3, 2019
16
Scottsdale
I tried that myself so that is why I took it into the Ford GT tech and he couldn’t get it either. Perhaps they changed the bottom platform of the group 25?
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
I tried that myself so that is why I took it into the Ford GT tech and he couldn’t get it either. Perhaps they changed the bottom platform of the group 25?
I would seriously doubt that. We've installed 3-4 Group 25's in the past 5-6 weeks. Make sure the foot is on correctly.
 

dr914

GT Owner
Feb 11, 2009
252
Marietta Georgia
my replacement was identical to the original one. A bit of searching for the bolt hole but really no problem what so ever
 
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BIGFOOT

GT Owner
Jan 18, 2012
739
Northeast
What is the current (available) alternative people are using instead of the Optima 25?
If any
Thnx
 

2112

Blue/white 06'
Mark II Lifetime
so battery replacement went very easily. Bought the Optima Redtop 25 at oreilly's auto parts for 91 bucks, had it in stock.

That is over $100 less than I am finding them for, but considering the dealer wants $440 with no estimated time of arrival, even the $199 I am finding the Optima for is a better deal than the elusive OEM copy.
.
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
The oem is standard red top with the GT sticker put on it. You can peel the old sticker off and transfer. The real original GT batteries were all black.
 
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Stef

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Apr 5, 2009
1,082
Southern California
The oem is standard red top with the GT sticker put on it. You can peel the old sticker off and transfer. The real original GT batteries were all black.

I kept my black original for a
paper weight/door stop 🙂
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Me too
 

usmcfred

GT Owner
Mark II Lifetime
Oct 26, 2006
546
Massachusetts
To be safe I would get another 12v lead acid battery and fuse it with 10 amps and plug it into the accessory port. The fuse may be redundant as the accessory port has one as well. This will protect you from things lights coming on by design or accident. If I remember correctly the quiescent current is about 20 to 50 ma and less with the car locked (strange). But open a door hit the brakes, touch a switch then SOL!
There shouldn't be any problem to do this. Make sure the battery is all the way forward and make sure the "foot" a the end of the long bolt is on correctly. We've done dozens of replacements and always get them clamped in well.


Are you sure it's not a miss-marked size 34 instead of the size 25, which is the correct replacement? Optima Red Tops come in several sizes. Best thing to do is measure the L, W and H dimensions and compare them to the Optima 25 published specs.

usmcfred
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
Did you verify with an OBDII reader that the adaptives were retained?
That's really a moot point, right? A battery replacement will reset adaptive learning as well as emissions monitors. Always.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
That's really a moot point, right? A battery replacement will reset adaptive learning as well as emissions monitors. Always.
Unless, as I have done and dr419 said in his post that I replied to, that he had connected the battery tender before changing the battery. In my case the emissions adaptives were retained. I was merely asking that poster to confirm.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
Ahh, yes. A 12v source plugged into the cig lighter would prob work... I've even heard of peeps using a common 9v battery on other vehicles. We'll have to give that one a try the next time we replace a battery where retained values are inconsequential.
 

Specracer

GT Owner
Mark IV Lifetime
Nov 28, 2005
7,081
MA
If you really want to save your OBD2 memory, there are also these (my battery jump pack has a 12v port):


I personally dont care, only have an anual inspection, and being "forced" to drive the car to get the monitors "ready", is fun. Drive em!
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
FYI, the 16 year old OE battery in my 2005 finally died. I know from participating in another car forum that the newer Optimas do not last anywhere near as long as the old ones. Those were very high quality batteries. The new ones are average quality. Expect 5 years or so.
 

dreimer

GT Owner
Mark II Lifetime
Feb 8, 2018
164
Ponte Vedra Beach, FL
My first time replacing the battery (Optima 25). I have a pulley and tune, cat delete, and live in Florida (so no inspection). Can I just replace the battery through the normal process? I see all the comments on hooking up battery tender, etc. but it seems that is more focused on passing smog inspection. I drive my car relatively often (about 4K miles in past 1.5 yrs). I just want to make sure I don't mess up anything with the tune and engine functionality.