Yes use a trickle charger. I store my Mustang for 4 months every Winter and it starts right up.
No, it won't go into battery saver mode on a battery tender. A battery will last longer on a good maintenance charger even if you use it every day, so I don't understand your "Only worry about a battery tender if it's something you do regularly." comment.
2024 Hybrid, i parked my Mav in a parking lot in northern Montana from Nov/1 to Dec/19 and then from Jan/9 to Mar/31, i disconnected the positive battery cable and had no problems starting up , the weather was a mix of -15 to 50 !
I can only speak directly to the fact that I typically drive my Mav once a week and even though I have hooked it up to a battery tender after five days the lights will not come on when you open the door. My personal experience is that the Mav has some time based programming to go into these battery saving modes that happen regardless of the battery state of charge. Simply turning the key on for a couple seconds any time before 5 days will reset the time. I have read other reports of people going on trips with the Mav left on a battery tender and getting the deep sleep notification after something like 2 weeks. I have never left it parked long enough to get that far to verify that part of it myself.
I've used a battery maintainer for weeks at a time without driving and have never had battery saver activate in 8 months of ownership, so I don't believe it's accurate to say that it will "activate anyway" on a battery tender, unless a battery tender isn't working as well as my maintainer. I have no experience with Battery Tender brand, but it sounds like it's not working as intended, or your battery is weak. Another option is that the maintainer that is failing to keep battery saver mode from activating isn't connected correctly on the ground side of the BMS and thus the BMS isn't recognizing the charge uptake.
I went through all this for months. The maintainer (Noco Genius 2 and then a Genius 5) is hooked up correctly. The battery tests good. If it was a battery issue or it was actually seeing a low state of charge putting the key on for 2 seconds would not change anything. When I drive it as soon as the engine is warmed up the stop/start functions which it would not if the battery was low. Are you saying that you can park your Maverick for weeks and when you open the door the interior lights still come on? Like I said, I have not personally had it go into the later stage battery saver mode since using the maintainer, but I have not left it parked for more than 7-8 days. I can't find the old thread. Maybe you're right and it doesn't go into full on battery saver mode on a charger but in my experience it goes into the first stage of disabling the interior lights and screens not coming on when you open the door after 5 days regardless of anything you do.
