When are you going fully electric?

[theone8181]

Just found this forum post today. It's a thread discussing the range drop of a Model 3 in cold temperatures (33% at -15C). One of the posters on the third page posted a table with their actual efficiency vs temperature which was interesting.

https://teslamotorsclub.com/tmc/threads/33-range-loss-in-cold-winter-conditions.106072/


I decided to graph it up to see the trend clearer (and converted it to Centigrade) (the last three points in the >25 Mile efficiency are extrapolations based on the trend line of the actual points). Outside of the anomalous 107.7% reading at 35 degrees there's a pretty good trend.

Now, for the UK it doesn't matter as much, temperatures only drop to -10 so maximum efficiency loss due to temperature would be around 25%. Not great, but liveable. For here temperatures get a bit lower which is why I did the extrapolation - I've never seen any actual data down to -30 or -40c. While it's probably not completely accurate at the extreme end it does tell a worrying story, suggesting to me that BEV's are not going to be a real option for a fair chunk of people unless we have a step change in technology (or come up with a way of heating batteries with a separate system). -30 isn't uncommon here, and further north -40 is common in winter. If that extrapolation is even remotely right something with a 300 mile EPA range at 10-30C gets a real world range of 100 miles at -35 (with pre heating of battery).

That also blows cost saving out the water as well. Suddenly electricity costs 3x the amount you think it would, and becomes far more comparable with petrol, even more so if you recharge at a commercial location rather than at home - which you'd have to do more as the range reduces so significantly.

And no, this isn't a theoretical study for me - the thermometer hit -35 a couple of times last winter during >100 mile trips. It does make me wonder if having a BEV as a primary vehicle will ever actually be feasible if I continue to live here. Even with the 350 mile BEV mentioned earlier I still wouldn't be able to do trip to my local ski hill without having to charge both directions when it's -30.

There may be solutions to this. Some people already use diesel heaters in their BEV's in winter to extend their range. Perhaps the use of similar systems on battery packs may help (although would be a bit comical) - alternatively (half joking admittedly) some form of radiation based heat like they use in space probes. Would be interesting if you crashed though...

Ouch at -50 you won't be doing many long trips. Is the drop in range just due to the temperature and the batteries or factoring in stuff like heating seats/windscreen and incar heating?

 

[Nasher]

At -50 you'd probably need to keep them heated permanently, or they just wouldn't hold much charge at all. Which would make it a bit of a false economy.

 

[Mercenary Keyboard Warrior]

At -50 jeez, remember watching a program some years ago about military testing in those sorts of colds and all sorts of things have issues there, rubber is like concrete in hardness but brittle etc

Ah got it, future weapons alaska special S3 E10

 

[bimbleuk]

I've yet to go through a winter with my BEV but as I have done a decent amount of research I'm aware that my 80 mile (typical) range will drop as low as mid-50s though even that was only down to -15 DegC as reported in a couple of reviews. So for my 34 mile total daily commute I do have a decent margin but I still have some doubts just like the first journey from the dealer with 50 miles to go and 70 miles on the "predicted" range indicator. It took a few journeys to become confident in it's accuracy. The range is adjusted for outside temp, battery temp (it tends to go up shortly after starting a journey as the battery heats up), drive mode selected and general driving style based on logged data.

Also at least one of those reviews had the car garaged over night but at least the i3 I have has a good battery/car prep mode when plugged in to be basically warm and defrosted when I need to leave. We'll see but in prep I've bought a fitted side/screen cover and will keep the screen clean to reduce the condensation and therefore AC usage. My only concern is how much the range may reduce further when sat in the company car park with no way to plug it in for battery warming.

I should have bought the range extender version and definitely shouldn't have sold my Celica to my neighbour

 

[McPhee]

I do agree, don't get me wrong, my view is that the tech that will win out is charging.
There is nothing to stop you having multiple charge options, things like embedded near field charging. But

My main point is that there would be nothing to stop having part fixed, part removable.

So take the 25kwh in 15 minutes.

Car 1, all built in, stops for a quick break, plugs in at supercharger, ready to set off in 15 minutes with 120 miles worth
Car 2, 60kwh inbuilt, a replaceable 25kwh battery, plugs in supercharger, replaces replaceable battery at same time, sets off in 15 minutes with 240 miles worth

Which car would you buy? If you hardly ever exceeded the range of car 1, probably car 1. If you regularly did longer trips I would bet car 2

The comparison is heavily loaded in favour of Car 2.

You're assuming a 35kWh battery can accept and sustain the same charge rate as the 60kWh pack. Also, adding 120 miles of range from the replaceable 25kWh pack seems very optimistic. And swapping batteries while the car is plugged in to, and charging from, a 100kW+ power source seems a bit dubious.

To justify the cost, Car 2 would need to offer a significant time saving. And that will only happen if your assumptions are correct. If the 35kWh pack charges at a more typical 50kW, and the 25kW pack cannot be replaced while the car is charging, suddenly Car 2 is slower.

 

[Mercenary Keyboard Warrior]

The comparison is heavily loaded in favour of Car 2.

You're assuming a 35kWh battery can accept and sustain the same charge rate as the 60kWh pack. Also, adding 120 miles of range from the replaceable 25kWh pack seems very optimistic. And swapping batteries while the car is plugged in to, and charging from, a 100kW+ power source seems a bit dubious.

To justify the cost, Car 2 would need to offer a significant time saving. And that will only happen if your assumptions are correct. If the 35kWh pack charges at a more typical 50kW, and the 25kW pack cannot be replaced while the car is charging, suddenly Car 2 is slower.

Granted, probably, but you just flipped it back the other way

Charging one segment whilst swapping the other isn't difficult, its keeping the two split, such as when replacing a hot swappable power supply.
The charging time of the smaller one doesn't matter, you arrive and swap in a charged one, so if its 10 minutes or 2 hours you don't care (although you would obviously if none were there charged available, just as you are if you arrive at a petrol station to find a sign "no diesel available")

Why would car 2 cost a lot more than car 1, it would need a few more bits of course, but a significant cost of EVs is the batteries themselves. Car 2 could in theory cost less to purchase than car 1, its got less fixed batteries. It would just have higher running costs.

Agree on the range thing, 25kwh would probably be more like 75 at current levels of performance. Wasn't really trying to predict the range, just to demonstrate the logic that having the two would actually increase the likely range for a 15 minute stop.

 

[McPhee]

Charging one segment whilst swapping the other isn't difficult, its keeping the two split, such as when replacing a hot swappable power supply.

I'm sure it is possible. Just seems a bit dicey to me, but that could be my lack of knowledge on the subject.

The charging time of the smaller one doesn't matter, you arrive and swap in a charged one, so if its 10 minutes or 2 hours you don't care (although you would obviously if none were there charged available, just as you are if you arrive at a petrol station to find a sign "no diesel available")

You're right. The charge rate of the smaller battery is irrelevant. But that isn't the battery that I was referring to...

Why would car 2 cost a lot more than car 1, it would need a few more bits of course, but a significant cost of EVs is the batteries themselves. Car 2 could in theory cost less to purchase than car 1, its got less fixed batteries. It would just have higher running costs.

Running costs, not purchase. More specifically, how much money would people be willing to pay to save a few minutes?

25kWh is equivalent to:
30 minutes on a 50kWh rapid charger.
10 minutes on a 150kWh rapid charger.
4 minutes on a 350kWh rapid charger.

Tesla were talking about $60-$80 to do a hot-swap, back when they were considering going that way (i.e. before the failed public trial run). That's not a trivial cost.

If you want to understand why battery swapping is a non-starter, have a read up on Better Place. Yes, there are ways to do it better. But that company's failure really highlighted the flaws in the idea, to the point where nobody has given it a serious go since.

 

[Mercenary Keyboard Warrior]

You're right. The charge rate of the smaller battery is irrelevant. But that isn't the battery that I was referring to...

I was using the previous guys numbers so take it up with him

 

[Amp34]

Ouch at -50 you won't be doing many long trips. Is the drop in range just due to the temperature and the batteries or factoring in stuff like heating seats/windscreen and incar heating?

That -50 point should be taken with a pinch of salt - real world testing would be needed to validate that as I have my doubts it's accurate - That said the car physically not working unless plugged in is probably accurate - you basically need to do that with ICE vehicles as well or the starter won't work (block heaters). It does pose challenges in some parts of the world though (Northern Canada and Russia for example). I wonder how many people in the Yukon have BEV's?

The -30 to -40 points are more worrying as that actually does affect millions of people. I'm sure someone will come up with something eventually, but at the moment it pretty much negates the possibility of a two EV household for significant proportions of Canada, the Mid West USA, Northernmost Europe and Russia unless we start installing multi hundred kWh in vehicles. Work vehicles in particular will have to have massive batteries if towing in cold weather.

 

[b0rn2sk8]

There should be some pretty good data from Norway, one of the big Tesla YouTubers lives there. It's likely he has done a video on it. I also think it would be fair to say you tend to drive a lot slower when its -30C so the effect on range will be less than you would think. Also once you start driving the battery is going to warm up quite quickly and if you had it plugged in before you left its not much different to using a block heater.

An ICE in -30 isn't all plain sailing either is it? Don't you have to mess with the fuel to make it work on top of block heaters you already mentioned.

EDIT: Here's one.

Description:

Yesterday it was extremely cold in Folldal, Norway. I went there to sleep in my car. In the morning the temperature was as low as -38°C/-36°C. The car started but it had some issues...

He slept in the car overnight with the heater running and this is how much power it used:

Range at 00:15: 316 km Range at 06:00: 241 km Average range consumed per hour: 13 km Average heater power: 13 km * 210 Wh/km = 2.7 kW Outside temperature when camping: -36°C/-33°F Temperature inside the car: 18°C/64°F Range mode on during camping

https://www.youtube.com/watch?v=capOgUHPz9Q

 

[Amp34]

There should be some pretty good data from Norway, one of the big Tesla YouTubers lives there. It's likely he has done a video on it. I also think it would be fair to say you tend to drive a lot slower when its -30C so the effect on range will be less than you would think. Also once you start driving the battery is going to warm up quite quickly and if you had it plugged in before you left its not much different to using a block heater.

An ICE in -30 isn't all plain sailing either is it? Don't you have to mess with the fuel to make it work on top of block heaters you already mentioned.

EDIT: Here's one.

Description:


He slept in the car overnight with the heater running and this is how much power it used:


https://www.youtube.com/watch?v=capOgUHPz9Q

Not that much slower. You'll still be doing 90-100km/h on a 110km/h limited road for example. The temperature is less of an issue, more whether there's snow on the road. The guy mentioned the battery warming advantage which is why he provided two sets of data (>1 mile and >25 miles) and it's relatively negligible.

At -30 unless you have an older, weak battery an ICE should start up just fine (I've started mine after it's been sat outside in -35c all night, with the block heater not plugged in, quite a few times and aside from a slightly longer time until the revs settle down (ie. a minute rather than 30 seconds) it's good to go. Fuel? Refineries and petrol stations switch over to a slight more vaporous petrol but from the consumer point of view there is no difference except for a slightly lower fuel economy (in the order of a few percent usually, not particularly noticeable unless you're tracking mileage).

Interesting about the Youtube (I can't watch it at the moment), what were the issues?

 

[bimbleuk]

Interesting about the Youtube (I can't watch it at the moment), what were the issues?

I've watched a few of his vids and the car was showing a service warning due to reduced power steering assistance, one tyre dipped below the monitor threshold (only about 0.1 bar) and the tyres were flat spotted from being sat in the cold over night.

In one of his Zoe vids he was driving at ~56mph at 0 DegC and the consumption dropped to 3.01 mile/kwh. In the last couple of days I've driven a Zoe at 10 DegC and it was getting up to 3.7 mile/kwh over a 48 mile journey. Doing the same journey in my i3 it was showing 4.2 mile/kwh. Better regen, less weight and skinny tyres helped that. So the effective ranges were Zoe ~81 miles (22 kwh battery) and i3 79 miles (18.8 kwh) battery.

Yet to experience 0 DegC or colder.

 

[Amp34]

I've watched a few of his vids and the car was showing a service warning due to reduced power steering assistance, one tyre dipped below the monitor threshold (only about 0.1 bar) and the tyres were flat spotted from being sat in the cold over night.

In one of his Zoe vids he was driving at ~56mph at 0 DegC and the consumption dropped to 3.01 mile/kwh. In the last couple of days I've driven a Zoe at 10 DegC and it was getting up to 3.7 mile/kwh over a 48 mile journey. Doing the same journey in my i3 it was showing 4.2 mile/kwh. Better regen, less weight and skinny tyres helped that. So the effective ranges were Zoe ~81 miles (22 kwh battery) and i3 79 miles (18.8 kwh) battery.

Yet to experience 0 DegC or colder.

Thanks, so not to do with the EV side of things then, more just random cold related things (my old vehicle used to have a problem with the HVAC bearing in the cold, the fan would rattle terribly until the car warmed up for example).

 

[bimbleuk]

Thanks, so not to do with the EV side of things then, more just random cold related things (my old vehicle used to have a problem with the HVAC bearing in the cold, the fan would rattle terribly until the car warmed up for example).

Yeah it worked fine though with reduced range of course. That also reminded me of another at -17 DegC where the thick charging cable was so stiff he had to use two hands to manipulate it to the car port. Just one of those small things we'll probably never experience here in our nice temperate country.

 

[McPhee]

Changes to the Plug-in Car Grant announced:

https://www.autoexpress.co.uk/car-n...rant-axed-for-phevs-and-cut-for-electric-cars

There's now just one tier; £3,500 for cars with <50g/km CO2 emissions and 70+ miles of electric range. Effective from 9th November.

I'm divided on this one. Ditching the £2,500 grant for short-range PHEVs will likely help improve PHEV range. But a drop in the Category 1 grant to £3,500 will be a bit of a blow to sales. It's also unfair on those who have orders in place; some of these cars have 3-6 month lead times. 4 weeks isn't enough notice.

 

[b0rn2sk8]

It’s a numbers game really, there are far more EV and PHEV getting sold and there is only so much money so pay out.

Lots of new models coming up in the next year or so, paying out £4.5k per car isn’t sustainable long term.

They are better off putting more duty on fuel to encourage adoption, but there isn’t really a big enough range available at the moment, particularly 2nd hand.

 

[Mercenary Keyboard Warrior]

The point in the reduction is that the prices are falling, so the subsidy required to tip in favour of the elec can fall

Its a bit like what has happened with the feed in tarrif and home generation

 

[Haggisman]

a drop in the Category 1 grant to £3,500 will be a bit of a blow to sales. It's also unfair on those who have orders in place; some of these cars have 3-6 month lead times. 4 weeks isn't enough notice.

So will this drop affect cars which are already on order?

Edit:
According to https://www.gov.uk/government/publi...018/upcoming-changes-to-the-plug-in-car-grant

I currently have a vehicle on order – will I still get a £4,500 / £2,500 grant?
Yes. As long as the dealer has correctly submitted the claim for the vehicle to OLEV, then it will qualify for a grant at the rates that were in effect when the car was ordered. However, the car must be delivered within 9 months of when the claim was submitted.

So I guess the question to ask is, when is the claim submitted by the dealer?

Hoping my order isn't going to be affected, since for me it will effectively be a ~13% increase in the cost of the car!

 

[McPhee]

IIRC the claim is submitted by the dealer at the point of delivery. But it's been 3 years since I bought the Zoe, so I may be remembering wrongly.

Hopefully there's a reasonable solution, or somebody points out the flaw in Mr Hammond's decisions and he delays the change.

 

[Amp34]

It’s a numbers game really, there are far more EV and PHEV getting sold and there is only so much money so pay out.

Lots of new models coming up in the next year or so, paying out £4.5k per car isn’t sustainable long term.

They are better off putting more duty on fuel to encourage adoption, but there isn’t really a big enough range available at the moment, particularly 2nd hand.

Not a fan of the idea of increasing fuel duty to persuade people to move to EV - all it does is penalize those that are least able to afford the move to EV. Instead I think Norway/Icelands methods make more sense, reduce the cost of the cars in the first place by reducing VAT.