Non static main battery location

[aerohead]

* it complicates the design, construction.
* it weakens the chassis, requiring additional reinforcement for torsional stiffness, crashworthiness.
* adding weight.
* wasting otherwise needed materials.
* if it fails-dangerous, the driver and passengers may be imperiled, with asymmetrical weight distribution, tire overloading, polar moment instability, loss of directional stability, rollover, spinal cord injury if not traumatic death.
* I don't see any upside.
* current lateral g-forces for production cars already exceed what most drivers are comfortable experiencing.

[Isaac Zachary]

One thing I would like to point out is that it would probably be more practical to add an adjustable ride height. Keeping weight down low will improve stability. But it seems the majority of people like a higher ride height. So maybe have a system that lowers the vehicle the faster it goes. Usually when you're going 75mph you're not getting in or out of your vehicle nor are you driving over potholes.

[j-c-c]

I wonder how many here actually drive PU's.

And know the real F/R weight bias range, loaded and unloaded, and then can give a real world realistic estimate how much drive distance is in each category.

Meaning, a PU is a horrible solution for any optimal COG goal, It always has been, with the new use of large batteries in electric PU's, we have an opportunity to improve, if not rectify the problem.

How this is complicated, has no upside, etc, is IMO, only a failure of imagination and will.
Selling the driving public on the solution seems to me, to be the biggest hurdle, kinda like here?

[Isaac Zachary]

Originally Posted by j-c-c

Selling the driving public on the solution seems to me, to be the biggest hurdle, kinda like here?

I get what you're saying. If anyone who isn't Elon Musk or Henry Ford suggests a new idea, it's automatically called out as snake oil.

For a few examples:

• Solar panels on cars: "The weight and aerodynamic drag will get you less range." "Most people might get 3 inches a week of range from them." "It's 500% cheaper, easier, more effective and more practical to just stick them on your roof."
• NEV's: "People have to have at least 300 miles of range and go at least 90mph for it to be practical." "I get on the freeway to work for about 1/4 of a mile and going around at 25mph would add 5 minutes to my drive, which is way too long." "How am I supposed to fit a sofa in one?"
• Aerodynamic cars: "Cars may be over 10 times less aerodynamic than they could be, but they're still ultra aerodynamic." "I want to drive a car that looks like a car, I mean, SUV that looks like an SUV."

[freebeard]

Instead of snake oil, contemplate the net cargo weight and center of mass, vs the mass of the battery pack and how far it can practically be moved.

As a 'first approximation' I'd venture that if the battery has half the weight of the maximum cargo variation, it would have to move half the wheelbase of the vehicle. For more than partial compensation.

This may be possible with planetary screws and segmented cable stays. But it eliminates the possibility of structural batteries.

[Piotrsko]

Originally Posted by j-c-c

I wonder how many here actually drive PU's.

And know the real F/R weight bias range, loaded and unloaded, and then can give a real world realistic estimate how much drive distance is in each category.

I do. Either the diesel F250 or the electric ranger.

The 250 with a full 3/4 ton load is 50/50, empty the front axle weighs 5000 ish pounds so it's really front biased maybe 63/37, worse when I drive. It's so nose heavy that it burns through front brake assemblies in any configuration. It does close to 800 miles per tank of fuel

The ranger is missing the engine which was replaced by the Kostov so it lost 200 lbs but it has 600lbs related battery hardware in the bed. Not sure about F/R BIAS perhaps 45/55 but it's weirder than anything else I've driven. Gets really twitchy on the freeway above 55. @18kwh, you get 40 ish calculated, I chicken out at 30

[aerohead]

Originally Posted by j-c-c

I wonder how many here actually drive PU's.

And know the real F/R weight bias range, loaded and unloaded, and then can give a real world realistic estimate how much drive distance is in each category.

Meaning, a PU is a horrible solution for any optimal COG goal, It always has been, with the new use of large batteries in electric PU's, we have an opportunity to improve, if not rectify the problem.

How this is complicated, has no upside, etc, is IMO, only a failure of imagination and will.
Selling the driving public on the solution seems to me, to be the biggest hurdle, kinda like here?

Spirit of EcoModder.com was almost 50-50 weight distribution as raced at Bonneville. And at a travel weight of 4,220-pounds indicated virtually zero-lift in the wind tunnel ( 33-lb front downforce and 22-lb rear lift @ 135-mph )
The National Highway Traffic Safety Administration testing failed to tip over the Tesla Model S. It can't be done!
When Cybertruck finally bows, at it's lowest suspension setting, the NHTSA may be just as challenged to get it's COG to work against it.
I'll be pleased when Tesla builds school buses. They have a horrible rollover track record.

[j-c-c]

Originally Posted by Piotrsko

I do. Either the diesel F250 or the electric ranger.

The 250 with a full 3/4 ton load is 50/50, empty the front axle weighs 5000 ish pounds so it's really front biased maybe 63/37, worse when I drive. It's so nose heavy that it burns through front brake assemblies in any configuration. It does close to 800 miles per tank of fuel

The ranger is missing the engine which was replaced by the Kostov so it lost 200 lbs but it has 600lbs related battery hardware in the bed. Not sure about F/R BIAS perhaps 45/55 but it's weirder than anything else I've driven. Gets really twitchy on the freeway above 55. @18kwh, you get 40 ish calculated, I chicken out at 30

The 250 numbers you note I believe support my original contention rather well, but can you also comment how often percentage wise you are driving at those load conditions?

Not sure how the Ranger applies here, is it still functionally a load carrying vehicle in the electric configuration?

[j-c-c]

Originally Posted by freebeard

Instead of snake oil, contemplate the net cargo weight and center of mass, vs the mass of the battery pack and how far it can practically be moved.

As a 'first approximation' I'd venture that if the battery has half the weight of the maximum cargo variation, it would have to move half the wheelbase of the vehicle. For more than partial compensation.

This may be possible with planetary screws and segmented cable stays. But it eliminates the possibility of structural batteries.

Well I'm contemplating, being PU's have usually a generous WB, and the fact without the conventional powered under carriage impediments/drivetrain obstructions with an under slung battery mount, the battery could move a considerable distance, would it achieve the ideal? 50/50, likely not, could it make a big improvement, my thinking is yes, especially a lot of other mass in a EV is also changed, and additionally no varying fuel tank weight consideration.

Not sure how the "structural battery" figures in here, as a movable battery would not add, as I see it, any structural aspects to the moveable battery application.

[Piotrsko]

Originally Posted by j-c-c

The 250 numbers you note I believe support my original contention rather well, but can you also comment how often percentage wise you are driving at those load conditions?

Not sure how the Ranger applies here, is it still functionally a load carrying vehicle in the electric configuration?

99% of 250 is empty with just me (shudder) mostly to charge battery or exercise engine. About 4-6 months between 10 gallon refills.

The ranger has a 500 lb available, but its hard to find something that will still fit around the battery. Primary city vehicle for 2 people perhaps 4 times weekly.