The Electric Car Thread

Re batteries, there are different guidelines for LFP batteries which are meant to be charged to 100% at least once a week.

There are numerous profoundly dull YouTube videos on the subject.

As the owner of a couple of relevant cars, I can comment…..  So if I blow £5k on a “runabout” with say battery health that gives 60-80 miles on a full charge today, what will that be in 2 years? 

In my experience as a long term owner, if you use it as a runabout with ‘gentle ‘ home charging, much the same.  The LEaf has a battery health indicator telling you what you’re buying.

Re. driver aids, if you don’t like them, in an EV6 you hold down the button for 3 seconds , they’re gone, till the next time it’s turned on and off.  Not sure if it’s as easy in most other cars, be they EV or ICE post 2022 or so.

I’ll be able to tell you about snow driving in an RWD car by tomorrow I suspect looking out the window….  But I have winters on, and that’s more important

If I’m preheating I want it using the battery that was charged at the cheap rate.

Preheating on octopus intelligent go is at the cheap rate.

In my experience as a long term owner, if you use it as a runabout with ‘gentle ‘ home charging, much the same. The LEaf has a battery health indicator telling you what you’re buying.

like I said it’s not what I’m buying, it’s what I’m going to be stuck with in a few years time, an unsaleable car with 20 miles of range doesn’t appeal. So if the rate of battery degradation isn’t as bad as people seem to flap about (he says doing exactly that) then great, that’s kind of what I want to believe.

By ‘Gentle’ Home Charging do you mean keeping it in about the 20-80% range either with a cheapo 7kW wall unit or even just a 13A plug overnight? As that’s the sort of thing I had envisaged TBH. No big wattage fast charging (not that these ‘older’ EVs take that), running the battery right down to ~5% or charging it to 100% unnecessarily…

I’d want to be able to get a few useful years use out of it still (say four as a minimum?), without too much maintenance stress. So buying a 16 plate Leaf or Zoe in 2025 (already a 9 year old car at that point) and running it until say 2029ish (by which time it’ll be 13 years old) to then either flog off or scrap depending on it’s value to someone else doesn’t seem insane.

On that basis are you saying you’d personally consider a ~16 plate Leaf or Zoe (non-battery lease) as a local runabout (doing 10-30ish miles a day)?*

*Note the intent is for this to be driven by a technophobic Woman who tends not to pay attention to things like gauges, and regularly forgets to charge her mobile…

Preheating on octopus intelligent go is at the cheap rate.

This is a very handy way to game Octopus for a cheap croissant cookery window.

If you aren’t needing to charge every day, is it possible to plug in and preheat without actually adding charge?

Not on anything i’ve played with. There are several devices that need to be on to start the climate system and connect to ground power. And AFAIK this will start the charging (unless you’re already at a SoC limit). The power will essentially go Wall box > Onboard Charger > Battery > Climate system.

how small top-ups relate to overall battery life in terms of charge / discharge cycles.

Bugger all. Charging damage is pretty much proportional to how fast and how full you charge. Charging slow and/or low, the damage is a fraction of a percent of that which you do supercharging from 0-100%.

since I can choose a FWD or a RWD EV I’d like to know what would theoretically be better in snow even if it doesn’t actually matter in practice.

Unless you’re buying something so old that it doesn’t have traction contols, ABS and all those other systems that have been around a couple of decades neither is better until you get to the track. I can get out of my place in FWD/RWD/AWD/4WD (and once in 6WD) with no issues, and that’s a steep dirt track in Scandinavia. It (as always) is people who aren’t prepared who cause the issues.

The BEVs i’ve had down there, the only one that struggled was the RWD prototype with completely uncalibrated traction control and ABS…

TBH, you’re overthinking it.

Well this kinda does, and kinda doesn’t fit here…..

Was at the local Lidl and about to inform this chap that this is EV charging, not motorbike parking…when blow me!

Got chatting to him – it’s a 15.7kWh battery, and about a 90kW motor.

Looked brill – just like a traditional bike (i was expecting an EV motorbike to be all futuristic). All the benefits of an electric car – smooth rapid acceleration, easy twist and go…regen…

What a wicked thing!

DrP

Thanks Mert – I suspected that was the case but good to confirm. I do mainly structural / suspension rig work so don’t get to play with running vehicles any more.

So if the rate of battery degradation isn’t as bad as people seem to flap about (he says doing exactly that) then great, that’s kind of what I want to believe

Battery degradation isn’t a linear thing.  You get more degradation in the first year or two then it flattens off, but after a while you start to get more chance of a cell failure which isn’t quite the same as degredation AIUI.  So that’s when a cell becomes ‘weak’ and does not hold its charge, the BMS will report this as degradation.  I think that with an early Leaf you might be running this risk a bit more, but I’m not exactly sure. The second generation (40/62kWh) seem to be better. The 30kWh models are reportedly worse than the earlier 24kWhs for battery degradation.

Thanks @mert I’m sure you are right on the over-thinking ?

Part of the issue is that I do enjoy pondering abstract questions like which mode is theoretically better even if the difference doesn’t matter, but I shouldn’t expect anyone else to care.

We’ve had exclusively AWD cars for over 20 years now. Ever since we came perilously close to getting stuck on a deserted highland road in a blizzard with an 18-month old baby in the back. Sold the car and bought a 4×4 the next week and it’s been AWD (with appropriate tyres) ever since. I’ve had to dig myself out of snowdrifts a few times but have never failed to get where I want to and going back to a 2WD EV still feels like a bit of a backwards step. But I’m sure you are right; in a modern EV snow performance is really all about tyres and dual-motor setups are really just about extra power.

I’m sure Mert is probably right, but doesn’t physics say that having double the area of grip gives an increased chance of moving?

(It certainly gives the software twice as many options for which wheel gets the power at any given time)

#oversimplification 😉

I’m sure Mert is probably right, but doesn’t physics say that having double the area of grip gives an increased chance of moving?

In terms of grip then the more tyre area you have the less pressure there is on each square cm of tyre so it’s more complex than that. However, you’re talking about FWD/RWD/4WD, and yes if you have four driven wheels you have more forward traction. But he’s saying that in his environment two driven wheels is enough to get you going, and that’s all you need to get to the end of the lane. You would be able to do it faster in a 4WD car but this is only useful if you are rallying.

I suppose nice crisp dry hardpack snow in a cold country is a bit different to slush with a wet layer underneath that’s going to freeze over night.. snow is pretty complex stuff.

Ever since we came perilously close to getting stuck on a deserted highland road in a blizzard with an 18-month old baby in the back

You’ll always get MORE grip in a 4WD but the big question is why weren’t you watching the weather forecast?  It’s not like snow can take you completely by surprise these days – the only times I’ve driven on snow in the last 15 years were when I deliberately went out to try it.

but the big question is why weren’t you watching the weather forecast

Because not everyone has the ability to choose when they have to make a journey and by what means?

I suppose nice crisp dry hardpack snow in a cold country is a bit different to slush with a wet layer underneath that’s going to freeze over night.. snow is pretty complex stuff.

We get both here. And glassy smooth ice.

in a modern EV snow performance is really all about tyres

TBH, in a modern anything, it’s all about tyres.

My 2WD i4 has big fat summer tyres on it. We live in a high area of south Lanarkshire in a hilly housing estate.

I took it out on a snowy day last winter to try it out. I parked it 5 mins later at the bottom of our road and it stayed there for 2 days until the snow melted.

It was truly awful, probably as bad as my last RWD BMW5 Tourer 15 years ago. Eldest son’s 71 plate Corsa with small wheels and crossclimates is seemingly invincible in up to a few inches of snow on hazard free roads ?

A question prompted by the recent cold weather – do some EV’s heat the battery in cold weather even when they’re parked up and not in use? I’m not referring to the pre conditioning that you can do before you drive to get everything up to temp.

It seems that in the current cold weather , when I park the car up, it has say 67% battery charge, and when I wake up in the morning it has reduced to say 66%, and at this point in time there has been no preconditioning, its almost like its using some power to stop the temperature of the battery getting too low – is this a thing that some evs do to protect the battery?

It didnt exhibit this behaviour when the weather was warmer

double the area of grip gives an increased chance of moving?

Yup, that’s the saving grace of AWD/4WD. It doesn’t however give you the ability to not slide into a ditch, or the back of the second to last car in the queue you’re about to join. That’s where the proper tyres come into their own. And driving sensibly.

As an interesting experiment i tried FWD, AWD and RWD this morning on the way out to the road. All allowed me to stop and start on the hill, it’s about a 1 in 4, with 50mm of fresh snow on frozen gravel. And i’ve got winter tyres on, not studded.

Only thing the AWD gave me over the single axle was the ability to accelerate like a bellend with minimal wheel spin (by bellend i mean ~50% throttle). FWD and RWD i could just drive off, part throttle, until a tiny bit of slip (then the TC engaged, as did the AWD.)

It didnt exhibit this behaviour when the weather was warmer

is this a thing that some evs do to protect the battery?

No.

A cold battery will report out slight less energy than a warm battery, as deliverable voltage and current will drop, so it’ll show slightly less SoC on the screen. You won’t notice a similar change when it warms up, as you’ll either be driving, heating the cabin or charging. All of which heat the battery. But also change the SoC more than the (mild) effect of heating.

Many will run cooling when the car is parked though, if the battery gets too hot.

Thanks @mert Were all three EVs?

I think I’ve flogged this horse far too much already so I’ll make this my last comment on the FWD/RWD/AWD EV point.

I don’t doubt that AWD is better than either FWD or RWD in theory and I don’t doubt that in practice tyres are the most important thing, followed by decent traction control. What I’m not sure about is whether (in theory) FWD is any better or worse than RWD in an EV.

We know that FWD beats RWD for traction in ICE cars, but that’s because all the weight is at the front. In an EV it would seem that the opposite is probably true and RWD is generally better. Looking at 0-62 times, for example, RWD EVs generally perform better as it seems hard to get the power down on a FWD EV without spinning the wheels. So, if all four wheels are on the same surface RWD should be better than FWD in terms of traction I think. What complicates things is that, on snow, the rear wheels are basically forced to drive in the snow compacted by the front wheels while the front wheels may be on the (grippier) fresh snow and can be turned to find a bit more grip. Whether this is enough to compensate for the traction advantages of RWD is harder to understand.

It’s a moot point really though. mert has done the experiment and any differences clearly don’t matter in practice and it’s just my overly analytical brain trying to make sense of stuff.

@molgrips I could give you all the excuses (returning from a trip away, alternative routes being much longer, changing forecast etc) but at the end of the day you are right, it was an error of judgement and if we had got stuck it would have been our own fault. But to err is human so I quite like having a big margin for error. Having said that, traction control systems (and tyres) have come a long way in 20 years, that 18-month old baby is now a 22 year old woman who can make her own mistakes and if not wiser I am now older and a bit more cautious. Winters here have also got milder so the need for AWD just isn’t as great as it was.

 But to err is human so I quite like having a big margin for error

That’s a fair point. The only time I have ever almost got stuck was when I  was working away from home and snow was forecast at home but not where I was.  It was a little worse than expected and I was late, and I almost got stuck on the small incline 500m from my house (with a big queue of cars behind me at rush hour). On summer tyres, because it was 2009 and the first snow we’d had in at least a decade. I don’t think I would risk it now because I’m older but also from talking to my Father in Law who deals with snow much more regularly and is consequently a lot more cautious.  When you’re young you think you can get away with more.

A seasonal question- what is the official STW line on 4 season tyres for EVs?  I think Michelin Cross Climate 2 are the general favourite but maybe EVs have some different requirements. I recall DrP had some different suggestions?

On a similar line, the general advice these days seems to be just to fit a good set of all-season tyres (e.g. Cross Climate 2) and use them all year round, but for those of us in the frozen north (Scotland) is it not still better to fit dedicated winter tyres in the winter and switch to summer tyres if it looks like we might get a summer?

maybe EVs have some different requirements

They don’t.

I recently put Continental AllSeason Contacts on the Merc simply because they were the cheapest decent option – in fact, on their special offer they were the cheapest decent tyre of any type.  Still lots of offers around.

They are almost as good as winters, but not quite – and not as good as summers. However the main advantage is that you don’t have to worry about wear or warm weather performance if it gets warm late in the spring but you still might get snow.

@DrJ ….

I’ve got Bridgestone turanza all season 6 on the AWD polestar…

I’d have happily got CC2 s for it but nil were in stock… But I’m actually happier with the Bridgestone as they come up better in the wet, but worse in snow… Being on the south coast it gets VERY cold and wet (-2 today) but we don’t really get snow….

So they suit me well…

Having all that weight and power, good tyres are a MUST…. With all the commuting I do, and with lots of standing water all year round, I’m pleased with my choice..

I’ve actually had all season tires on my cars for many years now…I see no downsides in use, and they are minimally more expensive (compared to non all season premium rubber…)

DrP

Barrie Crampton anyone? Interesting views on his YouTube channel.

V happy with the Kumho all weathers on the ionic 5. As above better wet dry performance with slight downgrade on snow is the right balance for uk albeit they deal with what snow we’ve had fine.
First time I’ve had all weathers as opposed to summers and winters on a second set of wheels and can’t see any real world disadvantage.

Being on the south coast it gets VERY cold and wet (-2 today)

Ha ha, Trust me that’s not VERY cold.

What do you do with the ordinary tyres you take off? Keep them in the garage “just in case”?

What do you do with the ordinary tyres you take off? Keep them in the garage “just in case”?

I’d wondered the same thing. When I was toying with the idea of all season or summer/winter swaps I figured replace old tyres with all seasons or get a spare set of wheels respectively.

Depends I suppose. If they’re fairly new then you can probably sell them. Maybe even get a trade-in discount some places?

if they’re part worn then I suppose they’re still saleable. Given the cost of tyres and their manufacturing effects I’d rather give them away to someone who will use them than leave them to rot in the garage ‘just in case’.

in the end I replaced my rear tyres first and since there were no readily available all seasons I just went for the non-EV replacement (no foam liner) which was cheaper, allegedly quieter(!), and works fine. Next car though it’ll be all seasons asap.

EV ‘servicing’?

I figured that the Tesla would tell me when it needed service intervention. It told me when the tyres were differentially worn and that they should be rotated or the rears replaced. My Model S prompted me when it needed the, now not done, coolant refresh. Any problems have typically been dealt with remotely or by a mobile service person, for example micro switch replacement on a Model S door handle or replacement of a Model 3 door handle because the chroming had peeled up on one end (all dealt with under warranty).

but I had an email this morning from my old MB dealership about BYD cars and a ‘great’ offer of ‘free servicing for 2 years’. IDK what they’d do. Check and fill the brake fluid? Screen wash? Tyre check?

What’s your ‘service’ experience for car that have fixed time/distance interval requirements? What did they do?

What do you do with the ordinary tyres you take off? Keep them in the garage “just in case”?

Complete set of spare wheels in the corner of the garage. I even made a rack for them, especially important as i’ve got 6 or 7 sets in there at the moment (i have a massive garage). Also, i’m using full winters, not all seasons. So it’s a noticably softer compound rubber and a very broken up tread. So they really don’t like it in the middle of the summer (especially not on the motorway!). By the same token, all seasons are useless for most of the winter (and illegal for all of it).

Thanks  @mert Were all three EVs?

Same car, but not an EV, a long range Hybrid, eICE on the front axle, electric rear axle.
Switching between hybrid and full electric modes gives me front and rear wheel drive (until traction control kicks in, then it switches to AWD). Or i can select permanent AWD. It also weighs a good lump over 2 tonnes, especially with me and two kids in it, probably 2200kg, weight distribution is fairly even with the hybrid set up, battery is in the tunnel (18.8kWh, about 90 kilos) rear motor/axle (107kW) etc adds about 80 in total, it’s a new motor and battery since last I looked at the actual weights so they might be a bit out!
But not a million miles away from an EV.

We know that FWD beats RWD for traction in ICE cars, but that’s because all the weight is at the front. In an EV it would seem that the opposite is probably true and RWD is generally better.

Several other things at play as well, the biggies being how much torque the engine can deliver at low rpm and how smoothly it does it. ICE also has the added complication of gearboxes (only talking autos here) and torque convertors. Then there’s stuff like suspension geo and weight shift and so on.
But generally speaking, to the rest of your post, yes.