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Piles of Tesla owners stranded at charge stations abandons their EV's.

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thm_w:

--- Quote from: tom66 on January 16, 2024, 11:32:33 pm ---This is pretty much what happens.  The car will still drive okay (at very reduced power) if the battery is cold but charging isn't possible until the battery has warmed somewhat.   Someone tested this, it took a good 45 minutes before their battery was hot enough to start accepting actual charging current.
youtube.com/watch?v=i-c8AUeKs5c

--- End quote ---

Interesting, surprised it takes that long with ~5-7kW heat going into the pack from -15C. 480kg of material + losses to the outside, maybe thats just what it takes.

floobydust:
The cars are under-engineered or... hiding something.

Tesla can easily thermal model the battery pack/heater, it knows ambient temperature, and can estimate the energy required to heat or maintain the pack temperature.
Tesla can easily thermal model the cabin temperature and heater, it knows ambient temperature, and can estimate the energy required to heat or maintain the interiour temperature.

The cold battery capacity reduction is huge and we should all hush hush about it lol. It's likely protecting against battery damage at the expense of a dead car.

Graph is a popular notion the media promotes and does it include the heaters running?

Siwastaja:

--- Quote from: floobydust on January 17, 2024, 03:54:12 am ---Graph is a popular notion the media promotes and does it include the heaters running?

--- End quote ---

Worse, it probably includes heaters running set for some ridiculously high cabin temperature like +23degC. -4F is just -20degC. Even my Nissan Leaf which has no battery heating, no thermal insulation, nothing fancy, gets more than 50% of the summer range at -20degC, even when it sits in the cold on my driveway, as I don't have a garage. For example last night it was -28*C for a few hours so the battery pretty much cooled down, in the morning it was -18*C and my consumption for the 60km drive was 22kWh/100km, when during summer it is like 16kWh/100km. But I did preheat the cabin and that is lacking from the number, so it would actually be 25kWh/100km. A lot more than in summer, but not even close to double. Then again, my cabin temperature is set at +16*C, which I feel is totally comfortable because it's obvious to me to put clothes on during winter time, and not count on parking right next to the door at the destination, which might be what American's are doing?

Siwastaja:

--- Quote from: floobydust on January 16, 2024, 10:36:55 pm ---But they would be really worried about battery Li-plating- which is terribly destructive to the batteries.

--- End quote ---

It really is, but remember it's a combination of three factors: high state-of-charge, low temperature, and high charging current. If you pick all three, you are going to have serious battery damage. But if you pick two, it's already better.

In real world, one usually does not need to charge a pack which is already nearly full, so it rules out one of the factors. (At the end of charge session, the battery pack has heated up already so charging can commence fully.)

In really extreme temperatures say -35degC though, charging currents need to be limited to very modest values even for, say, 50% SoC. It's probably tempting for a manufacturer to completely disable charging and take the PR hit. Now it is matter of taste whether you should be just pre-heating with 5kW and not charge, or pre-heat at 5kW and at the same time charge at 5kW. The end result is not too different - if you are expecting charging power of 100kW, and actually getting 50kW average out of the sessions, both options (only heat, no charging; or heat + slow charging) are very slow to start and the difference on average session charge rate is not big.

SeanB:

--- Quote from: Halcyon on January 16, 2024, 10:19:14 pm ---
--- Quote from: themadhippy on January 16, 2024, 10:16:56 pm ---
--- Quote ---I don't think that's ever been the case? Those living in cold conditions would be using diesel specific to those conditions
--- End quote ---
Certainly was in the past here in the uk,but then we've never been  geared up for the wrong type of  weather,even our railways suffer with the wrong type of snow

--- End quote ---

Maybe the UK is the exception. But you guys claim it's a heatwave once it hits 30 degrees. We call it a warm summer's day.  ;D

--- End quote ---

Remember once, while watching CNN at tea time (Gulf War 1, we loved the real time reporting, and often got a lot of pilots coming in to watch, because we had a TV set that could get the broadcast no problem, but their one was in the shadow area from the mountain), we were treated to a part of the news hour about how London was sweltering under a summer heat wave, and people were dying, and it was 31C. Turned to my colleague Raven, and asked him when was it 31C here. He replied it was around half past seven in the morning, and currently was just under 40C. This was indoors. And in winter.

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