[niblettc]

This is what scares me about electric cars. This type of design seems more likely to mean disposable cars. This is the automotive equivalent of a glued in non serviceable battery in a phone.

From an environmental standpoint this seems like a step backwards. It can be cost effective to replace entire damaged engines and transmissions even in older vehicles. People are keeping cars for longer, currently the average is over 8 years.

[boardwaalk]

There are many motorcycles with the motor as a structural component. It does not mean you throw away the bike instead of repairing or replacing the motor.

[VLM]

There's a big wikipedia article on the various vehicle frame technologies thru the ages.

https://en.wikipedia.org/wiki/Vehicle_frame

So my commuter car is a cheapie Yaris ICE not EV. Its lead acid battery lives on a shelf attached to the frame, kind like a body on frame by analogy, except instead of bolting a car body to the frame they're bolting a battery shelf to the frame. If they ripped out the battery shelf and embedded a shelf directly into the front quarter panel of the body, then theoretically the car would be a little lighter. Its probably not worth it for a small lightweight lead acid battery. Giant EV battery, on the other hand 5% lighter might be a lot of weight...

Maybe a more intuitive way to understand the difference between a unibody type design and a body on frame design, is to look at old pickup trucks and you can rip the pickup bed off the frame and the truck works fine because the wheels and brakes and all the parts attach to a frame, so a bed-less pickup truck is just a pickup truck without a bed. Now if you rip off the back of a unibody car the entire back of the car would literally disappear because there is no frame, the frame is the body. Like the suspension parts attach to the body. There is no separate body and frame, there's just "the back of the car".

So one way to build a EV is to convert an existing chassis by bolting big battery pack "boxes" onto the frame. There exists a frame of a car and you bolted boxes of batteries to it as an addon. But a lighter way, which takes a lot more engineering, is building the battery "boxes" into the frame itself; there is no separate battery box there's a compartment in the frame that holds the batteries. You can't replace the battery "box" or the frame separately because they are not separate they are the same piece of metal. Much more engineering, much lighter.

I would imagine you can replace the batteries just as easily in a unibody EV as a body-on-frame EV. But you can't replace the rusted out battery box on a unibody EV because there is no separate battery box, its engineered into the frame.

The biggest disadvantage of unibody designs is everything is embedded in everything else so in a body on frame car a minor fender bender you remove and replace part of the body. But with a unibody the whole suspension and drive train gotta go too. To replace EV battery in a body on frame design you simply remove the battery from the frame. In a unibody system there might be a lot more labor hours maybe you gotta remove all the wheels and doors and seats to yank out a substantial chunk of the middle of the car.

[varjag]

An average EV will last longer than 8 years. Early fears of battery longevity proved to be unfounded.

[ArchStanton]

Ideally the whole car collapses simultaneously.