Viewing 40 posts - 5,041 through 5,080 (of 5,717 total)
  • The Electric Car Thread
  • whatgoesup
    Full Member

    My i4 can do one-pedal or not (or adaptive where it decides for you which work brilliantly well in this car*), but either way it doesn’t seem to affect the regen-physical brake balance.

    When you press the brake pedal it doesn’t engage the brakes to start with, rather it starts the regen process. Only when you’re braking fairly hard i.e. beyond the capability of the motors to regen or the limits of grip do the brakes start to work. Given it’s rear wheel drive hence rear wheel regen only I hope that in wet / icy conditions it balances this out with the front brakes and doesn’t just effectively pull the handbrake on. With the icy weather coming up in next few days I’ll have an experiment in a suitably slippy, empty carpark.

    * I had an Audi Etron with adaptive regen. That was awful – whether you would brake hard or just carry on coasting when lifting off the accelerator seemed totally random. The i4 is really nicely calibrated and is both predictable and does exactly what I think it should every time. It appears to be witchcraft.

    mert
    Free Member

    Given it’s rear wheel drive hence rear wheel regen only I hope that in wet / icy conditions it balances this out with the front brakes and doesn’t just effectively pull the handbrake on. With the icy weather coming up in next few days I’ll have an experiment in a suitably slippy, empty carpark.

    Yes, this is exactly what it’s designed to do. At a certain point it’ll switch from rear axle only regen to rear regen/front friction to maintain balance. It also can lead to car sickness, excessive braking on the rear axle only.
    There’s also some arguements about limiting regen on accped release to a level that can safely be done on the rear axle only. Though i don’t know what the BMW strategy is, as i’ve only had a quick trundle round the car park 😀

    I had an Audi Etron with adaptive regen. That was awful

    It’s also really really really hard to do right.

    whatgoesup
    Full Member

    There’s also some arguements about limiting regen on accped release to a level that can safely be done on the rear axle only. Though i don’t know what the BMW strategy is, as i’ve only had a quick trundle round the car park

    116KW max regen for the RWD car. That’s plenty to lock the rear wheels up in slippy conditions.

    I’ll let you know what happens when trying it out on icy / frosty / snowy ground.

    whatgoesup
    Full Member

    116KW max regen for the RWD car.

    Edit – I doubt that’s all available from just lifting off – I’ll see if I can figure it out though.

    iainc
    Full Member

    let you know what happens when trying it out on icy / frosty / snowy ground.

    It was minus 6 here this morning and I had a play about, it seemed to work exactly the same as on a dry grippy road, which was a relief ! Not sure what’ll happen in snowy conditions..

    garage-dweller
    Full Member

    Sorry maybe a numpty question but I followed a model 3 the other day and the brake lights were on and off like they were being operated by a sugar loaded toddler who’d just discovered the light switch. Just wondering if they were utterly incompetent or this was some EV trait.

    Their driving style was very much “surge, slow, repeat”.

    In the Teslas if regen engages above some, fairly low, level the brake lights come on because the car is decelerating. It can look like folks are tap dancing on the brake pedal in slow moving traffic. Because of the deceleration, the brake lights are a reasonable warning measure.

    The relatively quick acceleration and aggressive regen may take some getting used to for folks used to, for example, a sluggish diesel ICE I suppose.

    Also the brake lights come on whenever the car stops. This seems common in most modern cars though.

    Thanks.  I’ve never noticed it before in quite such an extreme way.  I suspect a new to EV or just clumsy footed driver now I understand how that works. Following at a safe distance (as is my default) it wasn’t an issue just a bit odd to see. If it had been an ICE I’d probably not have noticed and the acceleration/deceleration would probably have been less marked I guess from your comments.  I’m yet to drive one as budget and function are not yet aligning for my requirements.  I keep looking and trying to learn though.  

    clubby
    Full Member

    Ordered winter tyres/ wheels for my iX3 so will see what difference it makes to range. They’re an inch smaller and also narrower, so won’t be a direct comparison. Seen a slight drop in this cold snap but haven’t done any long journeys this week. 

    molgrips
    Free Member

    The Hyundai had ‘adaptive’ regen added after an update, or “what the **** is my car doing now?” as we called it.

    prontomonto
    Full Member

    Related to EV’s and slippy conditions, any opinions on driving in snow with them? I ask because they’re often RWD and obviously automatic. I had a friend who sold his automatic RWD ICE car shortly after having a nightmare trying to get up a motorway slip road in bad snow.

    I’m only really considering a yearly (if even) tobogganing trip up local hills with the kids. Always drove FWD manual cars, carefully, and had no issues – with normal tyres.

    Daffy
    Full Member

    Our i3 and BMW 3 touring have been fine in the snow with winter tyres.  Even fairly deep snow and compacted snow seemed to be okay.  We live on a hill.

    DrP
    Full Member

    technology-regenerative-braking-chart-22tdipace412.jpg.ximg.s_12_h.smart

    This is a good graph showing “how much” each system offers to the braking load (taken from the LEAF website).

    I think I read the LEAF offers something like 0.8g (force) max as regenerative braking..anything above this uses friction brakes.

    ALSO… I know other cars use this function too, but not all, but the e-pedal (one pedal system) on the LEAF employs both regen and friction. I know some EVs with one pedal driving DON’T employ the friction brakes with this function. This you can come to a ‘moderately rapid’ complete stop with one pedal driving.

    I just use one pedal (e-pedal) mode all the time. Also, I never use the parking brake now. Which leads to pretty lazy driving, and when I jump in an ICE I frequently nearly let it roll away when parking!

    Re tyres and winter… I just stick Michelin cross climate 2s on all my vehicles and drive happy all year round!

    DrP

    multi21
    Free Member

    I sincerely hope these 850BHP 3100KG **** never make it to the UK

    https://www.autocar.co.uk/car-news/new-cars/tesla-cybertruck

    Musk also touted the Cybertruck’s off-road credentials: “you can drive over practically anything…

    …including pedestrians, cyclists, even that annoying Honda Jazz that’s in the way.

    didnthurt
    Full Member

    Coldest conditions my EV has been used in, it’s minus 4 here today. The battery life is woeful in these conditions, this is fine for my daily commute but is not great when you’re driving a distance especially at night. 

    Before you all start telling me how the heaters make a huge impact on battery life, I only heat the cabin to 18 degrees and use the heated seats and steering wheel instead. 

    didnthurt
    Full Member

    As for brake asist being used on EVs, IME this feels very similar to using engine braking in an ICE car that I was taught to use when learning to drive. Makes for a very relaxing drive. 

    molgrips
    Free Member

    Before you all start telling me how the heaters make a huge impact on battery life

    I think the actual battery temperature has as much or more impact than the heater, if you have a heat pump. My miles/kWh has gone down by about 10%, my total range down by about 20%. The car reported on a long trip that turning the heater off altogether would give 7 miles of extra range, but we were around 30 miles down.

    julians
    Free Member

    The cold weather certainly has a large impact on the cars range estimation algorithm, it’s currently about 20% lower than it was in warmer weather. I wonder if actual range is reduced as much as the range estimation states , or whether the range estimation is just erring on the side of caution.

    Presumably if you were to do a long drive, the battery would warm up and range should improve, but I dunno really.

    zntrx
    Free Member

    I think the actual battery temperature has as much or more impact than the heater, if you have a heat pump.

    eNiro with heatpump here. We’ve gone from 4.5 to 5 miles/kWh in August to 3.2 to 3.6 in the last week as reported on the trip computer.

    We’re in Glasgow (been -3 to +5), local trips across the city twice a day, 10 miles each way. Heater set to 19C, steering wheel heater used.

    perchypanther
    Free Member

    Genesis GV60 with a heatpump. Averaged 3.5m/kwh over a year. 4ish during the height of summer, 3ish when it’s subzero like now. 

    molgrips
    Free Member

    We went from 4.63 in September to 4.03 yesterday on the exact same trip.

    wbo
    Free Member

    The mighty Leaf is sitting in the garage as it’s -6C out we’re going skiing tomorrow so I need to keep the battery at least warmish to get it to load OK.  

    It’s ok enough in the snow on winter tyres. You do need to know how to drive on snow/ice which really boils down to how gentle to be. Efficiency on winters to summers is all over the place as it depends on what winters, what summers – Mich Alpin 6’s are good

    DrJ
    Full Member

    Snowy weather has revealed an EV thing – no hot engine to melt snow on the bonnet, so it slides off in a mass when you start to drive 🙂

    pedlad
    Full Member

    A day of driving in the cold yesterday and got 3 per kwh rather than cars 30k mile average of 3.5. No heat pump model  

    theres a nice new energy use chart since a software update shows trip% and live split between motors climate etc and my suspicion is after driving with and without climate control is this is far more responsible for reduced range than cold battery chemistry. 

    mert
    Free Member

    I sincerely hope these 850BHP 3100KG **** never make it to the UK

    They never will. Illegal in all sorts of ways.

    Unlikely to even make it out of the US, where they are already sailing very close to the edge of legality.

    Before you all start telling me how the heaters make a huge impact on battery life, I only heat the cabin to 18 degrees and use the heated seats and steering wheel instead.

    Switching AC on is what does the damage. Using heaters but not AC (if they can be separated in your car, many new cars can’t) will minimise the impact.

    But AC at 18 Vs AC at 21 when the outside temp is low, is a tiny difference.

    116KW max regen for the RWD car.

    That’s almost certainly the limit for the battery/invertor. It’ll be balancing a rear brake load like that with friction brakes on the front.

    Fag packet scribble says you’ll be looking at around 325-350kW of total brake before the rear tops 100kW, and that’s not an insignificant stamp on the brake pedal. 60-0 in under 5 seconds sort of thing. (Depends on lots of factors though!)

    It’s one reason why several manufacturers are looking at deleting rear brakes altogether. Once we get better batteries that can take more charge, 500kW+, I can’t see rear brakes lasting long, not in their current form anyway.

    molgrips
    Free Member

    Switching AC on is what does the damage. Using heaters but not AC (if they can be separated in your car, many new cars can’t) will minimise the impact.

    My Leaf has a heat pump but also a normal PTC heater. If you leave it on Auto in the cold it runs the heat pump, and the car will steam up with 4 people in. But you can turn on both heat and AC which obviously necessitates the use of the PTC heater. It did clear the windows, but thinking about it now I didn’t check the energy consumption after I did that so it may have been more responsible for the drop in range and I didn’t realise.

    julians
    Free Member

    Switching AC on is what does the damage. Using heaters but not AC (if they can be separated in your car, many new cars can’t) will minimise the impact.

    My car has a separate ac button to the rest of the heating, but switching the ac on or off makes no difference to the range estimation, whereas switching the heating on or off (actually it’s the fan on or off) changes the range estimation by about plus or minus 30 miles.

    Maybe turning the ac on or off would affect the range estimation if it was warm outside?

    I think the car has a heat pump and resistive heating according to what I read, but it’s hard to get any technical info to understand how it all works together as a system.

    matthewlhome
    Free Member

    Snowy weather has revealed an EV thing – no hot engine to melt snow on the bonnet, so it slides off in a mass when you start to drive 🙂

    Same happens with LED headlights.  And screenwash pipes.

    My top tip for winter EV driving is the -20 screenwash

    Metasequoia
    Full Member

    Tesla Model Y, heated windscreen wipers/nozzles; really good, and more important in EV as no engine heat.

    julians
    Free Member

    https://www.bbc.co.uk/news/technology-67591311

    Article mentioning phantom braking in tesla that somebody higher up the thread was talking about

    prettygreenparrot
    Full Member

    Article mentioning phantom braking in tesla that somebody higher up the thread was talking about

    Go to teslamotorsclub.com and you’ll see that the BBC are a few years behind on this story despite the newness of the German Tesla whistleblower. It’s been a thing for years – AI is just a statistical model after all. It will come with errors of both types.

    One fairly recent development in Tesla Autopilot surprised me – it now seems very sensitive to folks drifting on or over the lane dividers on motorways. Start to overtake someone and if they drift even onto the line as you approach the Tesla will brake to avoid coming alongside. Very conservative.

    I expect there is a high degree of dislike of Tesla in Germany for several reasons including the incumbent motor industry lobby and Tesla’s poor attitude towards unionisation.

    prettygreenparrot
    Full Member

    Switching AC on is what does the damage. Using heaters but not AC (if they can be separated in your car, many new cars can’t) will minimise the impact.

    Nope. A/C will not make as big a difference as putting the heater on. And having A/C off will increase risk of fogging up.

    Besides, who cares? The inside of the car needs to be comfortable! Preferably before I get in.

    FuzzyWuzzy
    Full Member

    For the Polestar 2 at least (and I imagine many other EVs) if the charger is plugged in and you do a pre-heat of the cabin it will also precondition the battery (it won’t do the battery if it’s not plugged in)

    uponthedowns
    Free Member

    Tesla Model Y here. Can’t say I’ve noticed much if any difference in range or consumption during the cold snap. Battery pre-conditioning before reaching a Supercharger is a game changer though. No change in charging speed compared warmer weather. The e-Niro I used to have could barely get to 35kW when the temp got to zero

    molgrips
    Free Member

    For the record, Tesla aren’t the only company that do this now.

    perchypanther
    Free Member

    I need to input a rapid charger destination in to the satnav to precondition the battery. Worth it though.
    I’ve had it charging at 231kW with the battery preheated.

    julians
    Free Member

    Can’t say I’ve noticed much if any difference in range

    I did read that teslas have two range estimation algorithms, the one that is shown all the time is just based on some fixed consumption figure and doesnt take into account your previous driving patterns/styles, or the outside temperature etc. And then there is the range estimation that is shown when you plug a destination into the sat nav, apparently this takes into account previous driving styles,previous consumptions figures, outside temperature and probably loads of other variables to give a more accurate estimate.

    Maybe the above is just an american market thing, and not in europe/the uk? but I can see how this approach it prevents a lot of the chatter you see on ev forums about range in winter being much less than summer etc

    whatgoesup
    Full Member

    25% range reduction in the i4 last weekend – circa 120 miles in temps between about -2.5 and +1 degC on Fri, 30 miles in about 1 degC on Sat and 120 miles in moderately heavy rain about 3-4degC on Sunday. Overall the car did 3 m/kw.hr vs the 4-4.1 that it managed for this drive in normal 15 degC ish driving, so 25% reduction hence a range reduction from 330 to 240 miles.

    molgrips
    Free Member

    Regarding range estimates – my wife’s commute is pretty good for efficiency – lots of constant 40 and 50s, and the Leaf seems to take a fairly long average. So even in the cold it’s reporting 145-150 miles of range on full charge. But when you take off down the motorway it’s less efficient so the remaining miles drops faster then distance covered. You’d think they’d be able to take your planned route into account, but I suspect that the dashboard ECU does one thing and the satnav does another thing and they don’t talk to each other.

    andylc
    Free Member

    My experience of Tesla model 3 pre-heat pump is that approx 20-25% reduction in range IF doing short journeys (ie daily commute) – in practice this is largely irrelevant as it just means it goes from being stupidly cheap to run to extremely cheap – £5 = 300 miles in Summer, 225 in winter.
    On longer journeys I can get much closer to Summer performance, so when it actually matters the reduction is much more mild – perhaps closer to 10% reduction.
    A bigger difference which I have often noticed is heavy rain. I assume due to rolling resistance this has an obvious effect on range.

    molgrips
    Free Member

    A bigger difference which I have often noticed is heavy rain. I assume due to rolling resistance this has an obvious effect on range.

    Yeah the same effect is observable in ICEs too but no-one cared, other than me 🙂

    jonnyrobertson
    Full Member

    I’m idly musing changing my car.  Running a Nissan Cube ATM which owes me nothing but is thirsty on fuel and getting on a bit (06 plate, 111k miles).  I don’t do many miles, about 6k a year, tops and few long runs, generally 25 miles a day to and from work. Could swap cars with the Mrs for long runs (parental visits) if need be.

    There will be pushback as any purchase requires funding but thinking about a Leaf around the 6-7k mark, providing I could get a decent return on the Cube,  There’s always a market for them so I don’t see why not.  No tax, no engine to service, no petrol to put in…. I know electricity doesn’t grow on trees and I don’t do many miles a year so would it be a worthwhile change to make?  To be fair I know what the answer from inside the household will be but just seeing what the hive mind reckons.

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