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0 pointsburnerthrow0081y ago0 comments

> Yes to a simple battery system!

But you realize this will make cold-weather range suck and on-the-road charging suck, right?

Preheating the battery and cabin on "shore power" is something EV buyers just expect at this point because that can consume 2-3kWh of energy (equivalent to 6-10 miles or 10-16 km). That's almost 10% of Slate's range (see below).

Preheating the battery about 10-15 minutes before you arrive at a supercharger is another expected feature. It can increase charge acceptance rate by over 50% (reduce charge time by 1/3).

The 150 mile range is extremely optimistic given the size of the battery and shape of the truck. With just 5% top and bottom buffers, you'd need to achieve over 3.1 miles/kWh... which is the consumption expected of a small aerodynamic sedan. I would bet real money that highway range (at 75 mph) for the small battery is less than 120 miles from 100% to 0.

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warble1y ago

Highway speeds are worst case scenario so maybe you're right but I doubt it.

Your charge rate acceptance number is surprising to me, I've never seen anything like this in my years of experience designing EV batteries. Preconditioning helps extreme fast charging but isn't necessary for 1-2 C charges at all unless it's very cold out.

There's some caveats to this depending on the exact chemistry but if anything the newer semi solid state NMC cells are even less dependent on this and can charge down to -20C.

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warble1y ago

Highway speeds are worst case scenario so maybe you're right but I doubt it.

There's some caveats to this depending on the exact chemistry but if anything the newer semi solid state NMC cells are even less dependent on this and can charge down to -20C.

j / k navigate · click thread line to collapse