Here’s some calculations I did when the truck was first mooted by the great Elon. I’ve fixed up a bit of the formatting.

First comes the losses experienced by a truck on its journey. In this case 900 km from Melbourne to Sydney. Note that this trip is along a perfectly flat road with minimum rolling resistance for asphalt. Even though the speed limit is 110 km/hr along that stretch of road truck are limited to 100 km/hr and no truckie would ever dream of breaking the speed limit, so the aero losses are 508 kWhr. If I increase the trucks speed to 110 km/hr the losses go to 615 kWhr and the battery weight up to 5.44 tonnes. Going faster certainly makes the losses go way up.

But is the 900 km range really necessary?

I mean fast charging is going to be a necessity if these things are going to work anyway, so an enforced 1/2 hour stop every 2 or 3 hundred km would not be such a bad thing.

Would it?

The Rev Dodgson said:

But is the 900 km range really necessary?

I mean fast charging is going to be a necessity if these things are going to work anyway, so an enforced 1/2 hour stop every 2 or 3 hundred km would not be such a bad thing.

Would it?

I did this when the truck was first ‘rolled’ out and it was being touted as a long range solution and I did the calculations on that basis. I suspect that electric transports may even be a really viable option for short haul situations but these calcs weren’t based on that.

sibeen said:

The Rev Dodgson said:

But is the 900 km range really necessary?

I mean fast charging is going to be a necessity if these things are going to work anyway, so an enforced 1/2 hour stop every 2 or 3 hundred km would not be such a bad thing.

Would it?

I did this when the truck was first ‘rolled’ out and it was being touted as a long range solution and I did the calculations on that basis. I suspect that electric transports may even be a really viable option for short haul situations but these calcs weren’t based on that.

OK.

For longer ranges they should just put the bloody containers on a train anyway :)

The Rev Dodgson said:

sibeen said:

The Rev Dodgson said:

But is the 900 km range really necessary?

I mean fast charging is going to be a necessity if these things are going to work anyway, so an enforced 1/2 hour stop every 2 or 3 hundred km would not be such a bad thing.

Would it?

I did this when the truck was first ‘rolled’ out and it was being touted as a long range solution and I did the calculations on that basis. I suspect that electric transports may even be a really viable option for short haul situations but these calcs weren’t based on that.

OK.

For longer ranges they should just put the bloody containers on a train anyway :)

The rolling wheel losses are way too low in that case :)

I find it kinda funny that Tesla, the company, sounds a lot like Tesla online with all the fanbois crediting him with stuff he really didn’t do.

Bogsnorkler said:

I find it kinda funny that Tesla, the company, sounds a lot like Tesla online with all the fanbois crediting him with stuff he really didn’t do.

I gave up, years ago, even trying to have a discussion about Telsa or Elon on most sites.

Bogsnorkler said:

I find it kinda funny that Tesla, the company, sounds a lot like Tesla online with all the fanbois crediting him with stuff he really didn’t do.

Lol, this

The Rev Dodgson said:

sibeen said:

The Rev Dodgson said:

But is the 900 km range really necessary?

I mean fast charging is going to be a necessity if these things are going to work anyway, so an enforced 1/2 hour stop every 2 or 3 hundred km would not be such a bad thing.

Would it?

I did this when the truck was first ‘rolled’ out and it was being touted as a long range solution and I did the calculations on that basis. I suspect that electric transports may even be a really viable option for short haul situations but these calcs weren’t based on that.

OK.

For longer ranges they should just put the bloody containers on a train anyway :)

Yeah, or road railers. In the US they just load the truck trailer whole onto a railway wagon. Truck haulage is only the delivery to and drop-off from the rail depot.

Battery weight about 5 tonnes – that may be about right. Batteries needed for heavy vehicles are – so far – heavy.
Even for cars the battery weight is a significant fraction of the total weight of the car.

I know some aerodynamics, so let’s check this one out.

Drag coefficient, I was expecting more than 0.4. There are at least two levels of faring used for reducing drag coefficients on trucks. But I knew that 30 years ago, things may have changed since then. Let’s check the web.

The following chart compares after-market drag reduction on a truck, in a paper from 2013. They didn’t get a drag coefficient below 0.57, well above the 0.4 quoted below.

Here’s another one. Again, we’re talking drag coefficient of 0.58, a lot more than 0.4.

So, using a drag coefficient of 0.57 instead of 0.4, that energy of 508 kWhr increases to 724 kWhr.

So trucks would need even bigger batteries.

mollwollfumble said:

Battery weight about 5 tonnes – that may be about right. Batteries needed for heavy vehicles are – so far – heavy.
Even for cars the battery weight is a significant fraction of the total weight of the car.

I know some aerodynamics, so let’s check this one out.

Drag coefficient, I was expecting more than 0.4. There are at least two levels of faring used for reducing drag coefficients on trucks. But I knew that 30 years ago, things may have changed since then. Let’s check the web.

The following chart compares after-market drag reduction on a truck, in a paper from 2013. They didn’t get a drag coefficient below 0.57, well above the 0.4 quoted below.

Here’s another one. Again, we’re talking drag coefficient of 0.58, a lot more than 0.4.

So, using a drag coefficient of 0.57 instead of 0.4, that energy of 508 kWhr increases to 724 kWhr.

So trucks would need even bigger batteries.

I was being very generous when I did those figures as I suspected I’d drag (sic) them out in front of some fanbois at some stage and I didn’t want them screaming that I was being unfair to their lord and master.

sibeen said:

I was being very generous when I did those figures as I suspected I’d drag (sic) them out in front of some fanbois at some stage and I didn’t want them screaming that I was being unfair to their lord and master.

Noted. I saw that you were being generous, eg. 100 rather than 110 km/hr, 900 rather than 1,000 km.

There may be some trucks with a drag coefficient as low as 0.4.