Ich glaube seit 5.1.1 macht er es immer mal zwischendurch, wenn die HVB mehr als 20% SoC hat.
Hier ein Auszug aus: https://www.macheforum.com/sit…ds/12v-battery-faq.32744/
Does plugging in the car keep the 12V battery charged?
NO! That is one of the biggest misunderstandings of the Mach-E 12V system that I see. The 12V battery is only charged when the vehicle is ON or CHARGING. If the vehicle is plugged in and NOT charging, the 12V battery is NOT charged. So if the vehicle was not driven or charged very long or very recently, the 12V battery is not going to be full. Some people think plugging in works like a 12V trickle charger, that is NOT the case.
But won’t the 12V automatically recharge when low?
Yes, but this is designated to be a failsafe against the battery going completely dead rather than a regular occurrence. This recharge event does not occur until the SoC is all the way down to 30-40% (quite low). This is well past the point of significant sulfation formation, and past the point the battery will freeze in cold temps. Repeated deep recharge events are stressful cycling on the battery and should be avoided. Automatic recharge is also disabled when the HVB is below 20%—the 12V battery will be allowed to go completely dead. Which is another reason it shouldn't be relied upon. For example, people with improperly wired dashcams have parked their car with <20% and the dascham completely drains the 12V battery, resulting in a lock out.
What % SoC does an OTA need to install?
It varies. Some OTAs require a higher percentage than others. It also depends on your current battery capacity and age. The exact threshold is calculated by the vehicle right before an OTA installs. The system ensures an adequate number of amps hours will be left in the battery after the OTA is finished to prevent bricking. If the reserve capacity calculation comes up short, the OTA will not install.
Longer OTAs such as 6.6.0 will typically require about 80% minimum. Shorter OTAs may only require 50%. This is why some OTAs are harder to install than others. Again, the exact threshold will vary from vehicle-to-vehicle based on battery capacity differences. If your 12V is failing and has poor capacity (as determined by the BMS), you may not be able to install OTAs even when charged to 100%. 12V battery replacement is necessary at this point.
How long does it take to charge the 12V battery to 100%?
This varies considerably depending on battery temperature, condition, aging, and charger output. A new battery at room temperature may only take 3 hours. In the winter, a cold sulfated battery may take as long as 48 hours to reach 100%. The last portion of the charging from 90% to 100% takes significantly longer. The charging rate is not linear, it's an exponential decay in rate.
How much 12V battery drain is normal while parked?
Ideally, less than 5% loss per day. There are two types of drain, standby (or quiescent) drain, and periodic drain. Standby drain is a constant 24/7 low-level load when the car is fully asleep. This includes listening for nearby key fobs or PAAK, or incoming cellular pings from Ford. The quiescent current can be read from the BMS with a scan tool, and should normally be less than 50 milliamps. If there is a problem with a module not going to sleep, or an aftermarket dashcam is improperly installed to constant-on power, the standby drain will exceed 50 mA and can cause the battery to drain too quickly. Excessive quiescent current will also prevent the BMS from reading the SoC correctly.
The other type of drain is periodic, this happens whenever the car is woken up. There are many things that can wake up the car, including opening a door, walking near the car with a key fob or PAAK present, forcing a FordPass data refresh, 3rd party apps pinging the car, periodic data upload/download session, etc. You may hear a clunking noise from the car when it’s woken up. Battery drain can peak above 10A for a short time until gradually decreasing as modules go back to sleep. It takes about 10-15 minutes for the car to go fully back to sleep after each wakeup, and will sap about 2-3% from the battery each time. In some cases, the car is woken up dozens of times per day, which can drain the 12V significantly faster than 5% per day.
