EVs when the temperature drops.
Discussion
I also think the idea that we should not put the heating on, instead relying on a heated seat and heated steering wheel is ludicrous, it's a sacrifice I don't want to make.
Similarly to how ICE cars have urban, extra urban and combined mpgs, an EV should have range based on same criteria AS WELL as based on temperature ranges. What works in Cali all year doesn't work the same in UK in January.
Similarly to how ICE cars have urban, extra urban and combined mpgs, an EV should have range based on same criteria AS WELL as based on temperature ranges. What works in Cali all year doesn't work the same in UK in January.
Tesla's don't have a heat pump so there's a significant energy drain for cabin heat. This really kills it in stop/start traffic.
A lot of other cars have a heat pump, or at least as an option, which helps a lot. There are still other losses in winter - thicker air, heating the battery, more likely to be raining etc. But it reduces the main requirement for energy.
A heat pump can provide c.4kw of heat for every 1kw of power. It makes a massive difference. Tesla have relied on having a much bigger battery instead.
A lot of other cars have a heat pump, or at least as an option, which helps a lot. There are still other losses in winter - thicker air, heating the battery, more likely to be raining etc. But it reduces the main requirement for energy.
A heat pump can provide c.4kw of heat for every 1kw of power. It makes a massive difference. Tesla have relied on having a much bigger battery instead.
jjwilde said:
Short journey first thing in the morning is the worst thing for EVs (and normal cars) in terms of range.
However, if you kept driving once it's warmed up the range will return to what you would expect.
It's just that first 10-15 miles which is the killer part.
Oh good....hardly anyone is going to do that..... lolHowever, if you kept driving once it's warmed up the range will return to what you would expect.
It's just that first 10-15 miles which is the killer part.
manracer said:
I also think the idea that we should not put the heating on, instead relying on a heated seat and heated steering wheel is ludicrous, it's a sacrifice I don't want to make.
Nail on the head.Us early adopter don't mind doing things like pre heating the battery, route planning, playing with heater settings, stopping to charge, looking at the weather forecast/wind direction (yes wind direction will impact on range).
But the mass car public will expect to get in their car and just drive, like they do now, the idea their brand new (and expensive) EV will run our charge 20 miles earlier than planned because they were driving into a 20mph head wind will not go down well!
Edited by gangzoom on Friday 8th November 18:15
gangzoom said:
You've never driven a heat pumped equipped Leaf in sub zero temperatures have you?
The Leaf gets hammered in winter as it can't heat the battery pack. No thermal management at all. A cold battery has a reduced capacity.Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
mcm87 said:
gangzoom said:
You've never driven a heat pumped equipped Leaf in sub zero temperatures have you?
The Leaf gets hammered in winter as it can't heat the battery pack. No thermal management at all. A cold battery has a reduced capacity.Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
Is the tesla worse than others in this respect?
mcm87 said:
The Leaf gets hammered in winter as it can't heat the battery pack. No thermal management at all. A cold battery has a reduced capacity.
Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
At a recent event Porsche claimed the 400+ mile range Taycan is at 30 degrees without aircon. At sub zero with the heat pump it falls to just over 200.Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
mcm87 said:
The Leaf gets hammered in winter as it can't heat the battery pack. No thermal management at all. A cold battery has a reduced capacity.
Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
If it was charged warm then goes cold, where does the energy go?Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
Certainly my Leaf range collapsed during "Beast from the east" event last year. Driving slowly in snow means the journey times are much longer so the heater use becomes significant. Looked like it would be just 12 miles or something it was astonishing. 2 battery temp bars showing. Most of the time it is 4 or 5 so doesn't usually appear vary very much.
When new the car had an indicated range of around 100 but in reality was more like 70 summer and 50 winter. With the advised 80% charging mode to prolong battery life and a buffer that's 35 miles. Still absolutely fine for my 22 mile commute to work.
gangzoom said:
It's my fourth winter with an EV, any who claims EVs are as easy to use in winter for long distance trips where time is important is talking BS.
For two car families, having one EV is not an issue, as if needed you can just take the combustion car.
It takes ALOT of commitment to have an all EV drivetrain even if you only do the occasional long trip in winter.
Saying range is fine 99% of the time is like saying your OK getting on an aeroplane that makes it to its destination 99% of the time. Bottas beat Hamilton by 4 seconds over a 1hr 33min race, that's a 0.1% difference between been the winner and first place of the lossers.
The 1% of trips may be really important, it may not, how important depends on the user/situation, but EVs at present are simply more inconvenient compared to combustion cars in some situations, especially in winter.
The fact EVs still remain more expensive to buy doesn't help. Paying more for less convince isn't something more people are happy to do.
The longer I own/use EVs the more convinced I am mass adoption is a long way off.
Good to get an honest appraisal from an EV user rather than the usual fanboy nonsense.For two car families, having one EV is not an issue, as if needed you can just take the combustion car.
It takes ALOT of commitment to have an all EV drivetrain even if you only do the occasional long trip in winter.
Saying range is fine 99% of the time is like saying your OK getting on an aeroplane that makes it to its destination 99% of the time. Bottas beat Hamilton by 4 seconds over a 1hr 33min race, that's a 0.1% difference between been the winner and first place of the lossers.
The 1% of trips may be really important, it may not, how important depends on the user/situation, but EVs at present are simply more inconvenient compared to combustion cars in some situations, especially in winter.
The fact EVs still remain more expensive to buy doesn't help. Paying more for less convince isn't something more people are happy to do.
The longer I own/use EVs the more convinced I am mass adoption is a long way off.
Edited by gangzoom on Friday 8th November 17:36
We are thinking of an electric car as a second car but they are not credible as the only car for most people (even if most journeys will be within range).
Also, we would lease not buy (a first for us), due to battery degradation and because I expect range of EVs to improve over the term of the lease which will hit residuals.
granada203028 said:
If it was charged warm then goes cold, where does the energy go?
It slows down the chemical reactions in the battery and increases internal resistance so, ironically, this generates more waste heat. Have you used a mobile phone or camera whilst skiing? The battery life is terrible until you warm them back up. You can also get a bit more life from a flat battery by warming it. If a traditional car 12v battery is on the brink it’ll likely give up in winter rather summer.In an EV you get more energy back out than you put in warming up a battery pack. That’s just when on the move, if you can warm it up whilst the car is still connected to power before your journey that’s even better. It’s also better for longevity as charging a cold battery is very bad, this is why cars limit their regen braking until the battery has warmed up.
A Tesla has a 7kw battery heater and a 7kw cabin heater. I think the Model X even has dual 7kw cabin heaters as the cabin is so large. That’s 14kw of power draw as soon as you start the car in winter! (This is from memory I haven’t checked so I may be slightly off). That’s not insignificant. A few short journeys and if you only have a c.50kwh battery in a SR+ and there’s going to be a huge hit to range. 2 hours driving at max heater and battery warming is half the pack gone (exaggerating, the heaters would never be on max that long unless you’re doing lots of very short journeys).
If you pre heat the Tesla the app has a symbol to show when it’s heating the battery. You’ll notice a bit better range if you do this before you leave and ideally when the car is connected to power.
Even with a warm battery and a heat pump you’ll lose range due to air resistance, bad weather, even a heat pump uses power and will lose efficiency is very low temps. But these two really help blunt the drop off.
mcm87 said:
The Leaf gets hammered in winter as it can't heat the battery pack. No thermal management at all. A cold battery has a reduced capacity.
Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
Is that theory based on fact or just wild guessing.Most EVs will heat the battery at the beginning of a journey or let you pre heat it beforehand. Then your hit in winter is much reduced - a heated battery combined with a heat pump for the cabin won't be take a range hit anywhere near as much as a Leaf or Tesla.
Here is the AAA report where they tested various EVs and in range all the way down to -6c and impact on range.
According to your theory an EV with battery heating and heat pump like the i3 should come first with least % reduction in range, and a Tesla resistive heating should come last right??
Have a read for your self....
https://www.aaa.com/AAA/common/AAR/files/AAA-Elect...
The summary is here, the two heat pumped equipped cars came both first and last, the Tesla came surprisingly close to the winner despite having a bigger cabin to heat.
But in any EV expect 30-50% drop in range at sub zero temps, thats BEFORE rain/wind which can take another 20% easily, or factoring cruising at lane 3 Mways speeds. All of a sudden even a 300mile+ EPA range EV is a sub 150 mile range car in the real world if you need to drive in winter, at speed, against wind in the rain.....
How many times have you got into a combustion car for a winter road trip and thought, oh its raining, I might not make it to my destination? Even in a £80k LR Raven Model S thats a very real question you have to ask your self before going on a 200 mile+ road trip in winter.
Edited by gangzoom on Friday 8th November 20:36
I’m not saying winter doesn’t reduce range, it does. But you can mitigate the effect with some planning.
In the scenario in the first post, lots of short but long duration journeys, a heat pump equipped car will lose less % range to cold. If the battery was pre heated it would lose even less.
That testing document is interesting, but my thoughts are:
They didn’t seem to do any pre heating of the cabin or battery, which would significantly improve results.
Their cold testing was bloody freezing. At -7°C the heat pump is probably below the floor at which it loses efficiency and switches to the traditional heater. I’m sure they would have had much better results for the heat pump equipped cars at -2 to 8°C, which we tend to spend a lot of time at in a UK winter (well, down in Kent where I’m based!).
Just summarising my experience. I used to do an awful lot of driving in a Model S and now have an i3 with heat pump. If I set the timer to pre heat the i3 before a long winter journey I can generally get within 10-15% of my summer range, unless it’s lashing it down/snowing. Or if I don’t plan ahead and just jump into a cold car I’ll lose about 30%. The Tesla lost way more on my same commute even with pre heat/planning. But - it had the extra capacity to spare so it didn’t really matter. The difference is now the Model 3 SR+ is here and this has a much smaller battery, potentially small enough that people might start to get concerned day to day and not just in the longer trips.
As more new EV owners jump in I expect these kind of comments to increase, but with planning you can drastically reduce the impact if you have home charging. It’ll never be as convenient as a petrol/diesel car, but then that’s true all year round.
There are also pros to EVs in winter as well - Never having to scrape ice off the windscreen, still cheaper per mile to run, I can sit outside a school with the heater on without being judged for having exhaust emissions etc.
The main thing I’m trying to get across is once you consciously consider the battery temperature as well as the cabin you might be able to plan sufficiently so that the reduction isn’t such an issue in your day to day routine, which is surely a good thing to be mindful of. This is also something owners new to a EV won’t be accustomed to (yet!). For me personally and my i3, I can halve the winter loss by simply setting my departure time the night before so the car warms the battery. I also get into a toasty warm car.
In the scenario in the first post, lots of short but long duration journeys, a heat pump equipped car will lose less % range to cold. If the battery was pre heated it would lose even less.
That testing document is interesting, but my thoughts are:
They didn’t seem to do any pre heating of the cabin or battery, which would significantly improve results.
Their cold testing was bloody freezing. At -7°C the heat pump is probably below the floor at which it loses efficiency and switches to the traditional heater. I’m sure they would have had much better results for the heat pump equipped cars at -2 to 8°C, which we tend to spend a lot of time at in a UK winter (well, down in Kent where I’m based!).
Just summarising my experience. I used to do an awful lot of driving in a Model S and now have an i3 with heat pump. If I set the timer to pre heat the i3 before a long winter journey I can generally get within 10-15% of my summer range, unless it’s lashing it down/snowing. Or if I don’t plan ahead and just jump into a cold car I’ll lose about 30%. The Tesla lost way more on my same commute even with pre heat/planning. But - it had the extra capacity to spare so it didn’t really matter. The difference is now the Model 3 SR+ is here and this has a much smaller battery, potentially small enough that people might start to get concerned day to day and not just in the longer trips.
As more new EV owners jump in I expect these kind of comments to increase, but with planning you can drastically reduce the impact if you have home charging. It’ll never be as convenient as a petrol/diesel car, but then that’s true all year round.
There are also pros to EVs in winter as well - Never having to scrape ice off the windscreen, still cheaper per mile to run, I can sit outside a school with the heater on without being judged for having exhaust emissions etc.
The main thing I’m trying to get across is once you consciously consider the battery temperature as well as the cabin you might be able to plan sufficiently so that the reduction isn’t such an issue in your day to day routine, which is surely a good thing to be mindful of. This is also something owners new to a EV won’t be accustomed to (yet!). For me personally and my i3, I can halve the winter loss by simply setting my departure time the night before so the car warms the battery. I also get into a toasty warm car.
A state of the art lithium ion battery can store approaching 1MJ/Kg. Water has a heat capacity of 4.2KJ/Kg/deg C which is relatively high. I've no idea the heat capacity of a cell is but if it was say 1KJ/Kg/deg C it would only require 2% of it's capacity to raise it's temperature by 20 deg C. So the energy required to heat a battery pack doesn't look to be that big a fraction of what it stores.
I think your theoretical capacity is ambitious - the c.28kwh usable battery in my i3 is 200kg+. It's 33kwh gross but it reserves capacity for longevity. As it heats it'll also be inefficient as it'll be warming up components around the cells and losing heat to the outside. I would expect it would be warming substantially more than the 200kg battery in practice.
Even if it used as little as 2 to 3 kWh to self heat 20 degrees that's up to 10% of the range you could saved by doing the same plugged in.
A Tesla battery is 500kg+ I think. It's a decent slab to warm up.
Even if it used as little as 2 to 3 kWh to self heat 20 degrees that's up to 10% of the range you could saved by doing the same plugged in.
A Tesla battery is 500kg+ I think. It's a decent slab to warm up.
mcm87 said:
It’ll never be as convenient as a petrol/diesel car, but then that’s true all year round.
That is the sadly the ultimately the same conclusion I have come to for EVs, yet EVs cost so much more to buy compared to a combustion car.Do you honestly believe most of the car buying public will be happy to pay more for a less convenient product??
I love EVs, we are not buying another combustion car ever again, but EVs have their flaws.
mcm87 said:
Tesla's don't have a heat pump so there's a significant energy drain for cabin heat. This really kills it in stop/start traffic.
A lot of other cars have a heat pump, or at least as an option, which helps a lot. There are still other losses in winter - thicker air, heating the battery, more likely to be raining etc. But it reduces the main requirement for energy.
A heat pump can provide c.4kw of heat for every 1kw of power. It makes a massive difference. Tesla have relied on having a much bigger battery instead.
I avgd around 280wh/m in my M3 on my commute into LondonA lot of other cars have a heat pump, or at least as an option, which helps a lot. There are still other losses in winter - thicker air, heating the battery, more likely to be raining etc. But it reduces the main requirement for energy.
A heat pump can provide c.4kw of heat for every 1kw of power. It makes a massive difference. Tesla have relied on having a much bigger battery instead.
this week at 1c incl a 10 min preheat and the heating set to 19c it’s up to around 330wh/m
Sums up EV ownership in 2019, the longer you own any EV the more you realise just how comprised they are in certain situations.
Don't forget the meteorological winter hasnt even started!
https://youtu.be/YyR4QNFEgJA
Don't forget the meteorological winter hasnt even started!
https://youtu.be/YyR4QNFEgJA
85Carrera said:
Good to get an honest appraisal from an EV user rather than the usual fanboy nonsense.
We are thinking of an electric car as a second car but they are not credible as the only car for most people (even if most journeys will be within range).
Also, we would lease not buy (a first for us), due to battery degradation and because I expect range of EVs to improve over the term of the lease which will hit residuals.
We've had an i3 as the only car in the household for a number months now due to delays in getting our Tesla Model 3 and it's perfectly credible assuming you can charge at home. 175 mile range in the summer which has dropped to about 140 this morning (-1 here at the moment).We are thinking of an electric car as a second car but they are not credible as the only car for most people (even if most journeys will be within range).
Also, we would lease not buy (a first for us), due to battery degradation and because I expect range of EVs to improve over the term of the lease which will hit residuals.
Our mileage use for the car is actually double the UK average (around 15k per year) and we often do 100+ mile round trips. Works brilliantly well and would do the same for most people I'm sure.
Agree on the residuals though, both our cars will be via EVEZY so we have the very minimum of commitment financially.
gangzoom said:
mcm87 said:
It’ll never be as convenient as a petrol/diesel car, but then that’s true all year round.
That is the sadly the ultimately the same conclusion I have come to for EVs, yet EVs cost so much more to buy compared to a combustion car.Do you honestly believe most of the car buying public will be happy to pay more for a less convenient product??
I love EVs, we are not buying another combustion car ever again, but EVs have their flaws.
The i3 we currently run costs us less than the 4 year old Mini Countryman SD it replaced did once you add everything up. The Model 3 we are waiting on is no more expensive than a comparable BMW, Audi, MB and will cost far less to run.
I find EV's far more convenient 99.9% of the time as wake up every morning to a full tank of juice and never have to visit a petrol station. If we charge publicly we always use one whilst shopping etc. so no inconvenience whatsoever.
If you can't charge at home or need to do regular 300 mile trips then fair enough, but we can and we don't so perfect for us.
gangzoom said:
Sums up EV ownership in 2019, the longer you own any EV the more you realise just how comprised they are in certain situations.
Don't forget the meteorological winter hasnt even started!
https://youtu.be/YyR4QNFEgJA
Definitely. If we had to 100% rely on public charging I wouldn't have gone EV. Fine with a Tesla if you have a local supercharger I'm sure but no good for everyone else.Don't forget the meteorological winter hasnt even started!
https://youtu.be/YyR4QNFEgJA
Edited by SWoll on Saturday 9th November 08:19
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