The 12 volt battery also controls the high voltage contactors , so it’s probably not going anywhere. You don’t really want the HV system connected at all times for safety purposes, and you’d usually always want the accessories running on low voltage too, otherwise when your interior LED shorts out its 500v DC finding…

I’m sure most of the accessory systems are reused from other vehicles, for example the blower motor that they use on all vehicles that size runs on 12 volts, the door locks and power window motors that are the same machinery as their other vehicles, just with a different housing, are made to run on 12 volts. It…

The serviceability isn’t designed for the end user. The battery EV is designed as a disposable vehicle for the end user. The battery packs are certainly not intended for the independent mechanic to work on and possibly not even the dealerships. The serviceability is for the manufacturer. Why? Because governments are…

Ford spring hose clamps can easily last 25 years IME.

Lots of screws: At least it can be opened without destroying it. Lower the number of fasteners then the adhesives, snaps, and other things that make it hard to service need to be deployed.

It runs all the accessory systems like the radio, lights, navigation, gauges, etc. It’s charged by the big battery through a voltage converter. Theoretically, you could build an EV without it and just run all the extra bits directly from the converter, but having a separate battery avoids a lot of complications.

12V is very safe. High voltage is extremely dangerous. Voltage is the size of the river of electricity.  

The latest Tesla Model S and X are using lithium ion 12v batteries, said to be good for the life of the vehicle.

Part of the reason too is safety. When the car is off, or after an accident, the main high voltage battery is completely disconnected from the rest of the car (probably by those big white relays) to reduce the danger of electric shock. The car needs the 12V battery in order to boot the computers and energize the relays…

Honestly, it's why everything still has a USB A port.  It's outdated but everything still uses it. Having that redundancy could mitigate a lot of problems with a simple, if inelegant solution.

I get the impression we’re just watching someone confirm their own opinions in minutiae that might be meaningless or misinterpreted. This would be so much more educational with someone who understood the thought process behind these designs and choices, which seems somewhat absent here. Is it NVH or fear? Who knows,…

I think the Lightning DOES use the same system as the Mach-E, just with a bigger battery pack. 

Counterpoint: Have you ever tried to find an intermittent electrical gremlin in a system with lots of cable and wire connections?  

That’s like asking “why isn’t the head gasket on my car’s internal combustion engine welded to the main block?”

I believe all current EVs, including Tesla’s, have the separate 12V. It has been a source of headaches on multiple vehicles, including Mach-Es. I assume a more integrated approach will come along eventually, but there may still be a separate, small battery for things like the clock and maybe data connection for…

Thank you, I believe that I am beginning to understand. So, Ford is still using legacy systems for the rest of the car, and using the 12v battery to power those systems in the event of the main power pack failing?

Because most automotive electronics are designed for 12V. Also if something happens to the battery pack its good to have a different 12v system for lights, door locks, ect. 

Ok, I’ll ask. Be gentle with your responses, noting that I am not an engineer.

I think there’s a good chance Ford built that battery with an eye to warranty costs.  It would be much cheaper to replace one bad module than the whole pack.  If they have the same basic module in the Ford Lightning, that’s a good cost-savings with commonality.

Ugh, given that he loves that Tesla nightmare of a cooling system, its hard to take him seriously.