Battery replacement procedure

[460Fred]

My ‘19 GT350 battery is done. No notice, just done.
I don’t trust Quick Lane to not mess things up. I have no choice there, my dealership sends battery replacement to QL.
I‘m going to Costco to get an Interstate and replace it myself.
Is there any “special” procedure or am I ok just replacing like I’ve done for decades?

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[matthewr87]

Be careful. If you do it wrong your FPC will blow up....

 

[WD Pro]

Neg first.
Battery comes out OK.
You will get a free KAM reset
Get the BMS reset afterwards.

WD

 

[jmn444]

I just replaced with a 96r 590cca motorcraft, and did this BMS reset procedure in the following link:

https://www.mustang6g.com/forums/threads/bms-reset-no-tools-required.151602/

On another note, my voltage seems to fluctuate more than before putting the new batt in, but not sure if that's a function of it learning or if that's what it was doing when the car was new as well... but varies between 13.3v and 14.5v pretty regularly and just replaced it 3 days ago. seemed like it was solidly 14.2-14.3 before, but I honestly didn't watch it that much till I started thinking the battery was giving up.


EDIT: I have zero way to know if that procedure does the same thing as a dealer bms reset.

 

[460Fred]

I just replaced with a 96r 590cca motorcraft, and did this BMS reset procedure in the following link:

https://www.mustang6g.com/forums/threads/bms-reset-no-tools-required.151602/

On another note, my voltage seems to fluctuate more than before putting the new batt in, but not sure if that's a function of it learning or if that's what it was doing when the car was new as well... but varies between 13.3v and 14.5v pretty regularly and just replaced it 3 days ago. seemed like it was solidly 14.2-14.3 before, but I honestly didn't watch it that much till I started thinking the battery was giving up.


EDIT: I have zero way to know if that procedure does the same thing as a dealer bms reset.

Thanks for that. I read to just disconnect negative for a few minutes then re-connect. I knew that was too easy.

 

[Postal Bob]

I just replaced with a 96r 590cca motorcraft, and did this BMS reset procedure in the following link:

https://www.mustang6g.com/forums/threads/bms-reset-no-tools-required.151602/

On another note, my voltage seems to fluctuate more than before putting the new batt in, but not sure if that's a function of it learning or if that's what it was doing when the car was new as well... but varies between 13.3v and 14.5v pretty regularly and just replaced it 3 days ago. seemed like it was solidly 14.2-14.3 before, but I honestly didn't watch it that much till I started thinking the battery was giving up.


EDIT: I have zero way to know if that procedure does the same thing as a dealer bms reset.

Normal battery voltage fluctuation. The voltage will be high when you first start the car, and gradually reduce as the battery gains a charge, And my old battery was constantly in the 14+ volt range just before it died. That's one sign that it's on the way out, and not taking a charge.
And yes, the BMS reset in the link, works the same as the dealers bms reset.

 

[jmn444]

excellent, good to know!

 

[galaxy]

Interesting enough, by not monitoring batter voltage, I seem to not have any fluctuation or oddities at all.

Funny eough though...I've seen more than a couple guys on the forums here chase a problem that didn't exist just from reading too much into what the voltage was doing. What's even worse is I've seen dealers replace perfectly good alternators/batteries based off the same.

Speaking for me, a bonafied electrical problem requires at least two symptoms; and fluctuating voltage in a normal 12V range is not one of them (or at least not that alone).

 

[jmn444]

Yeah I wasn't chasing voltage fluctuations, I was chasing killing two starters in a very short period of time, battery tested "weak", and it was 3.5 years old with a LOT of track/heat exposure so figured it was the potential culprit. I've also had two alternator replacements over the years, but those were diagnosed by the dealer when I had the wrench light and charging system error messages. Guessing those events didn't help my battery life either. I suspect the combination of track heat and weak battery was frying the starter, but that theory will be tested this weekend!

 

[460Fred]

Update…..Battery is still dead.
Costco has great prices on Interstate Batteries but no bueno here, they don’t have one and cannot order one. It is what it is. Ordered through Big O Tires which is very close by. $190 is full retail, I’m not going to shop around.

 

[jmn444]

96r size fits great, they only used the 99r because it was "lightweight" IMO.

 

[460Fred]

jmn444
Thanks again man!
Changed out the battery (Interstate MYP-T4) and followed the procedure in the link you shared. Bingo!
All is right in my GT350 world again.
Just an observation here…..A few days before my battery took a dump, my radio volume control stopped working. I did the negative terminal disconnect for a few seconds and that fixed the problem.
As with most new tech cars, let’s not forget to immediately have your battery checked when something strange happens. I remember my Charger had a weird electrical gremlin issue that came and went. That prompted a battery replacement to correct the problem.

 

[Postal Bob]

In these cars, when the battery starts dying, all sorts of weird electrical issues surface.

 

[galaxy]

Did you put it in a bag of rice??

 

[460Fred]

Did you put it in a bag of rice??

I laughed out loud yet have no idea what you mean.

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