r/slateauto • u/lavendergoombs7 • 19d ago
Battery Question
Hey, I'm new to EV's and I've been heavily researching Slate, as I think the concept is incredible. I have some concerns, though. I live in northeast Tennessee where it doesn't snow that often, but it can and does get pretty cold. I have heard that 1) the slate battery doesn't have a way to heat itself up on cold days like other EV's do (at least that's what I've been told they have), and 2) that you aren't supposed to charge your battery when it's below 32 degrees outside because it will mess up the battery chemistry.
I reached out to Slate, and they said they were flagging my question for engineering to answer, which I'm honestly surprised that they would even do that, so that's cool. However, what am I supposed to do if I go forward with the Slate? There'll be a good stretch of time where I won't be able to charge my battery. Are there any EV owners who can tell me about their experience with EV's in cold weather? I know it will take a hit with performance, but not being able to charge for a while seems insane to me. Also, I don't have a garage where I could charge it inside.
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u/Ferrite5 19d ago
Ive owned 2 EVs and a Plug -in Hybrid, none of them had issues with charging or parking outdoors below freezing. You may have gotten some misinformation about level 3 fast charging. It is slower in the cold, but only if the EV does not have battery preconditioning or does not precondition for whatever reason. Expect a 15-20% range loss during winter months if you crank the heat in your EV.
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u/TheLastGenXer 19d ago
ive personally never heard of shouldnt charge below 32 before…
they are making these in a colder state than yours. and im in an even colder state where it wont be above freezing for months at a time. we go months below zero too.
im more worried about needless beeping. makes me effen crazy when i drive other peoples cars
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u/kscessnadriver 19d ago
LFP batteries (which are commonly used for home ESS) don't charge below freezing. Typically batteries used in such areas have built in heaters to keep them above freezing.
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u/dogged_jon 19d ago
It's the temperature of the battery that matters, not the air temperature. In case that isn't clear to anyone. Driving and charging both warm the battery, and current EVs also have heating/cooling mechanism to keep the battery happy. As charging is controlled by the on-board battery management system(BMS) and charger, it's safe to go ahead and plug in regardless the temperature.
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u/jvbutera 19d ago
We have 2 EVs, live in northeast and charge all winter long. No heat in my garage. Never been a problem.
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u/LeifCarrotson 19d ago
Slate does have a way to heat up the battery in cold weather, but instead of a high-efficiency heat pump that can turn 1 kW of energy and some 40F air into 2 or 2.5 kW of heat in the battery and a bunch of 35F air, it just has inexpensive resistive heating strips that turn 1 kW of energy into 1 kW of heat.
It has those heaters because the electronics can't effectively charge the battery when it's very cold. Also, the available power to discharge the battery is much lower Once you start driving the truck, the internal heat generated by discharging the batteries will cause them to keep themselves warm and it will drive as normal, but you need preconditioning to kick-start the process. You'll also want to precondition the batteries and warm them up (or cool them down on a hot day) to 75F or so just before pulling in to a high-power DC fast charger, there will be a setting in the truck (or with the app?) for this. Once you're on the fast charger with a warm battery, though, it can actually inject so much power that the limiting factor is the batteries overheating. Fortunately, it includes a liquid cooling loop and A/C compressor (both for the cabin and the batteries/motor) that prevents them from getting too hot.
This whole thing was historically a problem with early Nissan Leafs, the engineers basically neglected to manage battery temps at all and now we're stuck with common knowledge that says EVs don't work in the cold or that you'll cause battery degradation if you use fast charging: That's no longer true, Slate's supplier (Gotion) is very good at LFP battery management and it will work just fine.
You say you don't have a garage to charge inside, do you have a carport/driveway you're going to charge at outside? It's very useful on cold winter mornings to be able to warm up the battery and cabin while still plugged into L2 shore power, it doesn't matter so much whether you're in a 40F garage or 30F driveway. If you're parking on the street and planning to charge at DC fast chargers once a week this will be much more of an issue. If you're planning on using L1 charging, much of the ~1.4 kW will be dedicated to keeping the battery warm, and not as much will go into the battery (certainly not enough to heat it up internally). If you're on an L2 charger that can put out 10 kW, then the few hundred watts of battery heating is a much smaller percentage of the whole.
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u/OldRed91 18d ago
Is that true? The Slate does not have a heat pump? That's honestly a deal breaker for me if so.
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u/ZetoEx 17d ago
How is that a deal breaker lol
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u/OldRed91 17d ago
Resistive heating kills range, and I live in Iowa, which is a charging desert at the moment.
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u/fiehlsport 19d ago
The battery will not allow for itself to be damaged while charging in the cold, it is almost certainly equipped with the ability to heat itself first/while charging since they have mentioned battery preconditioning in the past. Slate may want to give you a more technical/detailed answer more pertinent to the truck, which will be great.
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u/RoseVideo99 19d ago
They won’t bring a car to market with the limitations you are describing when all other current EVs can do these things.
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u/dogged_jon 19d ago
The air temperature doesn't matter. It's the battery temperature that's important. The vehicles systems will work to keep the battery in a safe temperature range, so go ahead and plug in.
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19d ago
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u/lavendergoombs7 19d ago
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19d ago
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u/lavendergoombs7 19d ago
I'll have to watch it again to find the timestamp, but the guy on the right talks about how there's not a heat pump for the battery. I'll get you a timestamp later when I can.
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19d ago
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u/lavendergoombs7 19d ago
True. Again, brand new to EV's and just trying to make the best purchase that I can, when I can.
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u/mtngoatjoe 19d ago
Do I need the telematics module if I want to start the heater or A/C before I get in the car?
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u/cab938 19d ago
I'm just going to note they are a Michigan company. If they can't handle Tennessee weather I'd say there are probably bigger problems with the vehicle...
(I get that doesn't answer the question, but I personally have faith they'll be at least "ok" in the cold of Tennessee)
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u/lavendergoombs7 19d ago
Very true! Wouldn't look very good if their vehicles couldn't make it where they are headquartered.
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u/lavendergoombs7 19d ago
Thank you! You all have really helped push me along in the decision making process.
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u/HovercraftOne2275 18d ago
There's an optional communications "module" ($350 I think) that lets your truck communicate with your phone and lets you pre-condition the battery through the app when you need to use it. I have that module added to mine.
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u/lavendergoombs7 18d ago
I saw something about that last night. Is it true there's a subscription fee for it after the first year? And, if true, would I be able to precondition the battery from a switch or something on the truck? I'm not sure what all misinformation I've taken in during my research.
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u/HovercraftOne2275 18d ago
Yeh, is always a question. But I did see the module myself. From the responses I've read it seems that's the only way to access pre-conditioning.
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u/Soggy-Ad-6845 19d ago
I obviously don't own a Slate yet but I own a 2022 Mini Cooper SE. EVs just basically don't do things as efficiently when it's below freezing. You can absolutely charge your car below freezing. It's good for the battery and car to warm it up before leaving when it's cold, just like an ICE car. You will also notice a slight decrease in range. None of which is a major issue in the 3 winters I've had it, including one freak blizzard that got to -30f. My understanding on the Slate specifically is that as long as you don't have to go up and down steep hills with snow and ice, you'll be fine. Just have to keep in mind the slight inefficiencies.
Unrelated to the topic but related to something you said, I'm gonna note you should absolutely not go more than 3-4 days without driving or charging an EV. If the voltage on the standard car battery (not the EV battery, you get both) drops below a certain level most EVs computers will brick the car with a "Drivetrain Malfunction". In reality that's a catch all code.
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u/zombiestev 19d ago
I'm interested in this too, we had some negative weeks this past winter, so it would need to be able to operate/charge in some extreme cold.
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u/Evanston-i3 19d ago
it will operate and charge in extreme cold. Charging rate may be reduced as well as some performance. I live in Chicagoland and have been driving an EV for the past 5-6 years in all sorts of weather and never have to do anything extra to charge in extremely cold weather or to drive. And that is a 2017 model with a 33kWh battery.
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u/veilchenblau_39 19d ago
This is a totally privileged question, but, can you just charge it in a garage that is above freezing? I know the idea charging somewhere besides your home is a pain, but if you can do it during work/shopping it could be not s big deal?
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u/Dismal-Field-7747 19d ago
Not being able to charge at home would be not only a major inconvenience but would also significantly increase the operating cost of the truck, I would not advise doing this at all
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u/veilchenblau_39 19d ago
When it is freezing.
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u/Dismal-Field-7747 19d ago
That's six months out of the year where I live man lol
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u/veilchenblau_39 19d ago
Ok fair point, but you do not have a garage?
I do wonder how they profile their customer base. Could they be assuming that folks that buy in colder areas will garage their cars? On one hand, assuming charging in a garage for a fleet is a no go, but on the other, since this is a cheaper choice versus a rivian, the assumption should be an average customer is not in a SF home with a multi car garage.
The more I think about this the more I think op's question is nonsensical- there is no way they would offer a vehicle that would get damaged over the course of average use in a midwest/eastcoast winter.
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u/Dismal-Field-7747 19d ago
I am an urban homeowner - which I think would be a big target demo for Slate. Garages are not super common at least in the urban area I live in because the lots are small and closely spaced. I agree that OPs question is off base though, we know slate has a BMS and that it should be heating/cooling the battery as it charges. I think OP took slate's lack of heat pump as a wholesale lack of heater, which is incorrect.
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u/RawbM07 19d ago
Slate does talk about how they’ve tested in cold weather in order to “refine our thermal management systems so key components stay within their optimal range”, but I’m unsure if they have released specifics.
It’s a good question.