Re:Tesla’s promises don’t compute with current physics and e...
by kumarvvr on Friday November 24, 2017 @11:38PM
(#15774468)
If all of them are connected in parallel, then you are right. It's like filling an array of glasses in the rain.
However the superchargers connect to the vehicle through a power port, which is relatively small. So it may not have as many parallel connections. You could split the charging to individual cells inside the car, allowing for parallel charging of all the cells simultaneously, but that means that the supercharger has to handle the cumulative power requirement of all the cells in parallel. So if you have 500 50W cells, then the super charger has to have the capacity to handle 25 kW of power. And that much power requires some very bulky cabling, even with a 3-phase supply.
Re:Tesla’s promises don’t compute with current physics and e...
by simonsarris on Friday November 24, 2017 @11:45PM
(#15774483)
The parallel connections are visible: https://insideevs.com/wp-content/uploads/2017/12/Tesla-Semi-...
Re:Tesla’s promises don’t compute with current physics and e...
by petre on Saturday November 25, 2017 @02:06AM
(#15774813)
Yup, definitely 3 phase. But then it has to supply a charger or an array of chargers on the vehicle that convert the power to DC, leading to increased bulk and costs. So we're back to the 501 terminal plug again.
Re:Tesla’s promises don’t compute with current physics and e...
by baddox on Saturday November 25, 2017 @02:51AM
(#15774930)
Perhaps they’re looking into some even superer superchargers for the tractors. It’s a shame they apparently publicly abandoned the hot-swap battery system, although I can’t imagine they’re not still working on it, especially for the tractors.
Re:Tesla’s promises don’t compute with current physics and e...
by petre on Saturday November 25, 2017 @02:01AM
(#15774800)
You'd still have to transfer the heat from the cells inside the battery. That would probably lead to a design with increased battery surface, maybe even a radiator or cooling lines.
Re:Tesla’s promises don’t compute with current physics and e...
by nimos on Saturday November 25, 2017 @02:40AM
(#15774898)
Already what happens. GM and Tesla use pumped liquid glycol for heating/cooling and some other companies use refrigerants.
Re:Tesla’s promises don’t compute with current physics and e...
by baddox on Saturday November 25, 2017 @02:49AM
(#15774924)
Interesting. I did not know that. I always figured they must need to manage heat, at the bare minimum by preventing huge draw for extended periods of time. Do you know where they radiate the heat, given that most Teslas don’t (to my eyes) have visible grill vents?
Re:Tesla’s promises don’t compute with current physics and e...
by greglindahl on Saturday November 25, 2017 @06:12PM
(#15778509)
All Teslas have a grill in the front, it's down low. The battery cooling system is shared with the cabin cooling system.
Re:Tesla’s promises don’t compute with current physics and e...
by petre on Saturday November 25, 2017 @05:41AM
(#15775401)
You only need to do that when charging the battery.
Re:Tesla’s promises don’t compute with current physics and e...
by baddox on Saturday November 25, 2017 @06:21AM
(#15775527)
Oh, do the batteries not heat up when discharging quickly as well? I know next to nothing about battery chemistry, but for some reason I just intuitively assumed they did. RC aircraft batteries can certainly catch fire if something causes them to discharge extremely quickly.
Re:Tesla’s promises don’t compute with current physics and e...
by petre on Saturday November 25, 2017 @08:31AM
(#15775898)
They discharge slowly during driving, unless you floor the acceleration while driving up a slope, but I'm sure there are some kind of limits in place, to prevent the user from draining an unsafe amount of power from the battery.
Unless I’m mistaken, each little cell should theoretically be chargeable in parallel, limited only by heat, massively parallel wiring, and the one massive input carrying ridiculous current.
In theory, if one cell takes 30 minutes to charge, all cells could be charged in parallel in 30 minutes. Obviously this is ignoring the challenges I mentioned, which generally don’t apply to the relatively small RC aircraft with which I have experience.