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Comment by jbm | Hacker News Reader

In winter, I lose 5-10% of my battery a day due to heating my battery. Tesla is nice enough to hide this under "You should keep your car plugged in all the time" messages. It's really a pain, especially if you have a relatively small battery to begin with. I have a 2019 Model 3 w/ a 50 kwh battery, and use 10-20 kwh on a regular basis; 5 kwh wasted means as much as 1/3 of my energy use is effectively waste.

I'd be very interested in seeing what they can provide for us. Improved battery chemistry for use in the far north is of far, far more value than yet another 5 person car for 1 person driving in San Francisco.

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When I bought a Model 3 last year I knew full well the issues with charging, temperature capacity loss, battery heating, etc. What I was surprised by was loss of regen! If the battery is below 20F or so then the firmware will only give it a trickle of regen braking. After all, it's effectively very fast charging, which a frozen battery can't handle.

I wonder if regen braking going to zero is behind some of the horror stories of sudden unexpected range loss in cold temps.

> In winter, I lose 5-10% of my battery a day due to heating my battery.

Exactly! That sounds like a drawback when you state it like that, but what it actually means is that this magic battery doodad needs to provide 90-95% of the performance of its existing, mature competitor (assuming no other drawbacks) just to be break-even in the market. You don't disrupt markets with numbers like that.

> what it actually means is that this magic battery doodad needs to provide 90-95% of the performance of its existing, mature competitor

The problem is mostly that it does the battery draw when parked.

Solid electrolytes are coming some day soon, so that we can let it freeze without killing the cells.

Right now, the Tesla is hard to use in a winter sport season unless where you're driving has a charger or underground parking near a plug point.

I can drive up hill to a nice ski resort, spend 3+ days taking the bus with all your shoes on without touching the car.

With the batteries, they'll just run down when parked, so I cannot park it for a whole week outdoors like I can do with my Subaru.

And with the low battery + low temps, it will not charge back up going downhill so the expected range drops massively by the time you're downhill.

Once you navigate to a charger, the car starts running the heater and driving down range further.

Watching the car battery eating its own range while driving to "Donner pass road" on your way out of Tahoe or Reno feels rather appropriately horrific.

I can't speak for a modern subaru, but I've not owned a single ICE vehicle that would work in this scenario. The battery would be dead. An electric one has the option to be plugged in and avoid the problem. Just because we haven't put the infrastructure in place for it doesn't mean we can't. We should do so, just like we did for gasoline.

???

What kind of clunkers have you been using that lose charge on the 12 volt after just 3 days in the cold? I've occasionally left my ICE car out in the cold for a week without using it and it never once even crossed my mind to worry about whether it would start after that; I've never had that issue on any car built in the last 15 years.

There are entire nations where this is the scenario all winter.

If your ICE car battery was dead after sitting a week in the cold you had a bad battery. I drive my car once every couple weeks and it regularly gets to -20 here in the winter and have never had an issue because the battery in my ICE vehicle is good.

that, or you have some broken thing connected that draws way to high idle current.

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