Batteries are like steak now, mine cost $300 with a pair of terminal protectors added. But it would cost me a lot more to get stuck on the side of the road in the desert where I drive a lot to go to different drag strips in Nevada. And my charging monitor shows the higher capacity one works a lot less to keep up.

 

'Modern' computer controlled starting systems are very sensitive to voltage and amperage... they definitely will work fine, take you to the store and refuse to start when you come back out ten minutes later. Instead of appearing 'weak', it either has ENOUGH juice or it doesn't... there is no try, it's either do or do not.

 

Im going to guess you left the cobb port reading plugged into the obd2 port ?

Most likely the culprit.

 

.
You are only partly correct on auto starts function.
The system has a Dc to Dc inverter located in the Body Control Module that checks the Battery Voltage before operation.
If the Battery is deemed not to support A-S-S, the system is inhibited and message to manually start the engine is displayed.
At this point it's a Battery load situation to allow the Modules, Pump and supporting functions to work under Battery loading conditions.
At this point the Battery should be able to manually start the engine.so the vehicle is not left stranded.
It's an early warning method that something has to be addressed before total failure occurs.
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The DC to Dc is to power 5 modules that are a must have, will have high enough voltage to function and to power a fluid Pump in the Transmission or the vehicle will not start or move.
Any fault in the system or driver action not permitted, will inhibit the A-S-S system.
There are more than 30 possible items that will inhibit A-S-S.
So everyone just thinks it's a Battery fault when sometimes it's not in a complex system like this.
A no start later is some other issue with Battery charge and/or drive time or to many starts in a short time interval on an aged Battery.
Have to look at the whole picture.
Good luck.

 

Don't see anything where he referenced A-S-S. He said the exact same thing I said earlier. The battery either has enough voltage/amperage at initial startup to turn the starter, and it then cranks and starts, or it doesn't. It's very common for a battery to fail today with no warning due to how quickly they start, because of all of the precise computer controlled parameters.

I fully charged my OEM battery when it failed to start at about 8 years old and got maybe another week out of it before it failed to start again. Charging it again did no good, so I figure it failed internally. At 8 years, I figure I got my money's worth and replaced it. My OEM Corvette battery did the same thing, except it lasted 11 years. It goes on a battery tender probably 6 times a year; the other vehicles that are driven all of the time get a full battery tender top-off a couple of times a year. Right, wrong, or indifferent, I believe the top-offs help the battery survive longer.

 

Ford batteries carry a 3 year warranty. I had 3 replaced for free by the dealer in 3 years on my 22.

 

Prefer not to have to count in the factory warranty, I take long trips too often. The new battery is not working as hard and fully expect it to go several years. Runs everything with 1/2 volt less active charging. Can tell it’s not working as hard.

 

Replaced the battery on my 2022 Lariat a while back. I was continually getting the battery save messages. I mainly use the truck for pulling my boat in the summer and an occasional ride to town. After 2 weeks or so of no use the truck gets really hard to start. One time on my way to town, 35 miles, the battery was so low that the gauges were all screwed up. I would keep mentioning it to the dealer and they kept telling me to put a charger on it if it wasn't used for more than two days. I told them good luck with that, it was a new truck under warranty and if it didn't start, they could come and jump it. I did give in and take it to pool league every couple weeks so after that so it wouldn't get too bad.
It finally seemed to get weaker and weaker, so I gave in and charged it to get back to a full charge. Took the negative cable off the battery and waited 4 hrs for it to settle, 12.2 volts fully charged, basically dead. Studied up a bit and decided to get away from Ford batteries. The standard battery in my truck was a agm H6 760 cca, I replaced that with a H7 850 CCA agm Everstart from Walmart. Truck doesn't even hesitate to start like before, even when sitting for some time. Best $190 I have spent.

 

these trucks need a upgraded battery. Too many electronics in them. 760 cca is less then the ford battery in my 67 Mustang.

 

My window sticker says 8 year battery warranty