Author Topic: EV tidbits  (Read 311 times)

rcjordan

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EV tidbits
« on: November 23, 2021, 03:28:54 PM »
Things I'm seeing while delving into ev forums.  These first two definitely aren't being touted by the sales departments or fanbois...

Running the AC reduces range by as much as 40%. (Data scarce so far, but I'd been wondering what the compressor load would do.)

Tires have a significantly shorter life on evs attributed to the higher torque.  Some of the ev trucks & suvs are fitted with high-$$ semi-custom tires by Pirelli.  (Lots of confirmations.)

The colder the weather, the lesser the range.

Rupert

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Re: EV tidbits
« Reply #1 on: November 23, 2021, 05:58:45 PM »
Quote
The colder the weather, the lesser the range.

And it drops off big style apparently, and not just because the heater is running.
... Make sure you live before you die.

ergophobe

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Re: EV tidbits
« Reply #2 on: November 23, 2021, 06:21:23 PM »
>>Running the AC reduces range by as much as 40%

Actually, this is something I have seen mentioned a lot in articles. A/C "costs" a lot in an ICE vehicle too. Running the heater in an ICE vehicle is almost free though - some pumping and fans to move that excess heat around, but the engine has to get rid of it one way or another.

Tesla has become the leader in range not just through bigger batteries, but by looking at every system in the car that uses energy. For example, apparently there's a pump for some kind of cooling fluid (not transmission obviously... something else) that typically runs all the time. They added a thermostat so that they can turn it on only when temperature reaches a certain point. Apparently they have extended their range by saving 0.1 watts here and 0.1 watts there, over and over.

And here's the kicker - all that self-driving kit takes electricity If you want a full autonomous electric vehicle, you're going to sacrifice range. How much is not clear, because the prototype stuff uses more energy than the production versions will.

>>The colder the weather, the lesser the range.

Another weakness of the Lithium-Cobalt battery. It is temperature sensitive, I believe more so than other batteries. I know for certain that when it comes to recharge resistance, it is much much higher when it is cold and it much more susceptible to this than other battery chemistries. This is the "tails" to the well-know "heads" of thermal runaway.

rcjordan

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Re: EV tidbits
« Reply #3 on: November 30, 2021, 02:41:19 AM »
Rivian R1T's first real-world towing test shows 62% range loss
https://www.teslarati.com/rivian-r1t-towing-test-range-loss/

ergophobe

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Re: EV tidbits
« Reply #4 on: November 30, 2021, 03:55:18 AM »
Who would have guessed? Article doesn't say what the range loss is on a tank of gas.

Drastic

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Re: EV tidbits
« Reply #5 on: November 30, 2021, 12:46:23 PM »
And only towing a 4k lbs car and trailer. Maybe half of the rated capacity. Looks like about 160 miles on a charge roundtrip.

rcjordan

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Re: EV tidbits
« Reply #6 on: November 30, 2021, 03:36:25 PM »
>loss

There is some chatter that even carrying a full-size spare tire mounted on the rear hatch causes noticeable loss of range.

Travoli

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Re: EV tidbits
« Reply #7 on: November 30, 2021, 04:19:34 PM »
>Tires have a significantly shorter life on evs attributed to the higher torque.
They are heavy vehicles, too. I drove a couple EV sedans at an expo. Both were close to 6,000 lbs.

It was my first time driving EVs. They exceeded my expectations, and I'm excited to make the switch when range/charge times improve.

ergophobe

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Re: EV tidbits
« Reply #8 on: November 30, 2021, 05:17:20 PM »
They exceeded my expectations, and I'm excited to make the switch when range/charge times improve.

Mary Barra (CEO of GM) says this, though amended to read "range/charge times/price" is what they are hearing from customers. She says that once price and charging infrastructure hit certain breakpoints, it will be a mad rush.

If there are incentives to recycle rather than resell clunkers, the transition to electric could be very slow then suddenly very fast. I'm reading John Doerr's* "Speed and Scale" and that's his goal - get price down and then get into a rapid shift. And it had better happen, because it has to happen fast or else...

*Doerr is the guy who convinced VC firm Kleiner Perkins to become the first investor in Google and early investors in Amazon, Slack and many others. He also is the one who convinced them to back Fisker instead of Tesla, a choice he says still smarts. His latest book is his roadmap to, as he says, preventing the climate crisis from becoming a climate catastrophe. Kleiner Perkins is now about 50% "green tech" having begun shifting in 2007.

rcjordan

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Re: EV tidbits
« Reply #9 on: November 30, 2021, 05:54:35 PM »
>heavy

The Rivian pickup weighed in at 7,148 pounds, which is massively heavier than any midsize or full-size truck. Ram threw the kitchen sink at the TRX and it still only weighs 6,396 pounds. Typical full-size trucks are more like 5,000 pounds.

We Tested the 2022 Rivian R1T and It's the Quickest and Best-Handling Truck Ever | Edmunds
https://www.edmunds.com/car-news/tested-2022-rivian-r1t-is-the-quickest-and-best-handling-truck.html

+

But even the owners of smaller sedan models were confirming that tires were wearing quickly.

2022 Tesla Model S/Curb weight
4,561 to 4,766 lbs
« Last Edit: November 30, 2021, 06:38:49 PM by rcjordan »

ergophobe

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Re: EV tidbits
« Reply #10 on: November 30, 2021, 08:03:24 PM »
>> 7,148 pounds

That's an interesting number. California chain control laws have a breakpoint at 6,000 pounds.

Quote
Requirement 1 (R-1): Chains are required on all vehicles except passenger vehicles and light-duty trucks under 6,000 pounds gross weight and equipped with snow tires on at least two drive wheels
https://dot.ca.gov/travel/winter-driving-tips/chain-controls

I think if it's 4WD you have an exception, because the next level is
Quote
Requirement 2 (R2): Chains or traction devices are required on all vehicles except four-wheel/all-wheel drive vehicles with snow-tread tires on all four wheels.

I think the law was written before your basic truck got so beefy.