Same is true for an ICE car. Eventually the 12V will be dead and you’ll need a jump. I would familiarize yourself with the procedure to pop the frunk through the bumper access panel. And then learn how to remove the panels to get access to the 12V. Or even drill the access holes to get at the 12v connection points without removing panels. It will make a jump start that much easier.
Maybe you will get a low 12v warning, but you sure won't get a "it needs replacement warning". People replace 12v batteries all the time for no good reason. "It died" is usually BS, because the true way to know that is to charge it up and then load test it. People just go buy a new one for no reason.
Can you safely remove the battery and take it to be tested just in case it needs to be replaced or will this effect the onboard systems if it is removed for say two hours?
We have asked Ford to send a notification when the 12V battery is severely degraded, but they haven’t implemented a replacement warning yet.
The batteries themselves are very good quality. I usually get 6+ years out of my Motorcraft 12V batteries. It’s the management of them that’s the problem.
It won't get to 100%, unless it's actively charging or being driven. If you put it on a Battery Tender, it can take a week or more to get near 100%.
