It's the title of your video that is wrong. Regen isn't bad for range, driving incorrectly is bad for range and that applies to all cars. Hypermiling has been done for years, it's just good anticipation, at least with regen you get some of the energy back. Oh and if you really want to slide that i3, Google i3 roller mode. Enjoy.

Of course you're right! Preference 1: continue moving. This way you can keep your kinetic energy. Preference 2: regen. This way you can win back at least some part of it. Preference 3: friction brakes. Not good for anything, but can stop your car quicker :) Plus, if BMW still uses same composite on i3 brake discs as they uses on mine 5 years ago, you should better use the friction brakes at least once a week, before they rust away... But there's another interesting point for your engineer heart 😉 You can apply same rules of energy transition not only for braking, but for the speed, too. I drove a Merc EQV for a long weekend recently. First as usual, but the consumption was ridiculously high. I took this as a challenge and tried to reduce it. So instead of a cruise-control driving, I tried to adjust the speed in a way to preserve the most possible energy. Driving up a hill, you would let your speed drop somewhat, instead of keeping it steady at any cost. Driving down the hill, you would let it increase above your target speed. Then when the hill is flattening, you'll take your speed excess to roll out longer into the valley, until the car slows down back to your target speed and you start pushing again. Adding just 20km/h variation to my speed on a mountain road gave me around 20% less consumption! I didn't measure it specifically, so no exact numbers here, 20% was the consumption meter in the car. I didn't take exact same route to put down a valid measure. But still, the saving was quite significant, and didn't cost me any time at the end - the slowness at ascending was recovered by the quickness of descent (watching the speed limits of course). It would be really interesting and fun to see someone doing such an experiment: constant speed vs. speed variation by +X/-X km/h in regards to the consumption 😏

Regen itself isn't bad for range, it's an overall plus for range. Driving brake-heavy will certainly hurt your economy, petrol, EV, whatever. But that's really a separate thing than the regen. I realize that's a bit picky in technicalities, but the devil is often in the details. Not sure why someone here seems to think regen is bad on battery, etc. Don't exactly see the problems this would inevitably cause.

Maximum range is about transfering as much of the energy stored in the energy store (battery or fuel tank) into the unavoidable drag. By "unavoidable" i mean the things that cause drag that you can't as a driver do anything about, ie aero drag and rolling drag. The kinetic energy temporarily held in your cars mass as it travels at a non zero velocity can be used with 100% efficiency to overcome drag, and it can be partially recovered by an electric car using regen, or completely lost in an car with an internal combustion engine either as brake friction or powertrain losses (engine friction & pumping losses / parasitics). So for any given average speed, the best possible option is to accelerate to that speed and stay there. In reality of course on real roads this is not practical mostly. Hence when we change speed we really should only ever slow down by coasting and here the KE is going with 100% efficinecy to over come drag, and as that KE bleeds away to drag load, the car slows. ON an EV like the i3, this "coasting" is actually deliberately mapped into a fairly wide pedal zone (wider zone in eco mode btw) that sits with the traction motor at zero torque, ie coasting (a tiny amount of energy is still being used to overcome iron and copper losses in that eMachine of course, but it's pretty tiny) and this is displayed on the i3 by the swing-o-meter sitting slap bang in the bottom middle of its arc, neither driving nor recuperating. if you have to slow at a greater rate, then use regen, which is easy in the i3 because it has a lot of regen mapped into the accel pedal for it's one-pedal driving. if you have to use the friction brakes ie press the brake pedal, then you have "lost" ;-) as in the i3 the brake hydraulics are not locked out or modulated to allow regen first, because the car is designed to be driven one-pedal for the vast majority of the time

Dear Mark, Just your title for this video is misleading. All the points you make about energy loss when using kinetic energy to charge the battery are correct but you are putting some energy back into the battery rather than just losing it as heat. But the main point you make is so true. If we all read the road and the traffic conditions then Electric or ICE we shouldn't need to use the brakes very often. That's the important point. Perhaps this video should have been called "Not reading the road is so bad for range".

Great videos about this car. Nice job Mark!

Regenerative braking is about recovering energy that would otherwise have been lost. In town driving I've found that I can end up with more range than I started out with thanks to the recovery of energy and generating energy on hills. To say regenerative braking is bad for range is incorrect, driving style will always lead to better energy use if you plan ahead for the road and conditions. Avoiding speed change will be better for an EV or ICE car, it's all about making the most of what you have.

Arrive to depart, rather than arrive to park behind queuing traffic is a fundamental HGV mindset.

I drove into town today with 59% battery. The journey had quite a bit of downhill and slow-moving traffic on the 5-mile route. After lots of regen slowing the car down, the GOM said 60% battery when we arrived. Free journey! Only problem is that I had to drive back again, uphill.. 🤔

I know this video is 1,5 years old but you should test the “regen” on motorway with speeds over 60mph. Will the regen (letting of the gas) be stronger OR lighter between Eco Pro / Comfort / Sport -modes? After 2,5 years of BMW PHEV (plug-in hybrid electric vehicle) ownership I believe this is true to some extent, but its greatly affected both by the “model year” AND the technology under the skin. For BMW PHEV’s different driving modes affects greatly how strong the “regen” is or in some cases it is disabled completely (this varies with the speed which the vehicle is moving). Thus I find a bit odd that Mark is saying that in i3 there’s only one setting for regen? Under all the settings under various driving modes there's no "B" or regenerative braking force or such? For example (yet again BMW PHEV’s) the regen in Eco Pro -mode is different than in Comfort or Sport -modes. Also in the newer BMW PHEV’s there’s this … how to say it, “coasting” option automatically engaged: The ICE or EV motor is decoupled from the gearbox & rest of the drive train system and shut off. Kind of “start & stop” system but while vehicle is moving on the motorway. From the BMW technical bulleting: "A hybrid-specific coasting function is triggered at speeds between 40 and 160 km/h (25 - 99 mph). As soon as the driver releases the accelerator, the combustion engine is switched off. In addition, recuperation of braking energy is reduced to the level required by the onboard power supply. The car therefore runs on the minimum possible energy consumption and with the lowest possible mechanical resistance". -This will greatly reduce the drag which the petrol engine normally creates. It’s actually surprising how long distance modern motor vehicle will just roll when there’s no resistance & drag from the engine. I’ve experienced this with my former 2018 BMW 740Le PHEV which had this option under Eco Pro -mode. And this actually increased both petrol and EV-range by quite a bit. BUT this “coasting” option was only engaged at speeds greater than 40kph / 25mph, when vehicle was travelling slower, it used regen like in Comfort -mode. And if driven with Comfort or Adaptive -modes the vehicle would just “engine brake” with regen system all the time -> negatively impacting the overall "range" of the vehicle. Then I bought an BMW i8. This one generation older hybrid powertrain does not have “coasting” option under Eco Pro -mode. When in Eco Pro the vehicle regens just like in Comfort -mode and the regen is actually stronger than 7-series ever had. Albeit the i8 is 800kg lighter than my 7-series was. Even at quite big downhill section the i8 will just slow down when Eco Pro or Comfort -modes. My 7-series never ever slowed down even at mild downhill, not even Adaptive -mode. If that thing was in Eco Pro, it would gain speed like a car in Neutral rolling freely. Could this (lightweight, older technology) be the case with i3 also? Because for example the much newer BMW i4/i7/iX will “coast” (only in Eco Pro -mode) and the regen will not reduce the range similarly than / if driven with Comfort / Sport / Individual -modes.

I think what you are saying with regards to energy saving is more relevant to your car with only one setting of regen, so as soon as you come off the throttle you are effectively braking, enter other makes where there are several modes you can coast, where as in your car you are still using power. 100% agree with reading the road etc. I would like to see a test done to show which is the most effective setting, I suspect it’s counter intuitive for the reasons you have highlighted. With minimal allowing you to shut off demand and coasting on kinetic energy alone.

Spot on. Two questions: When do the friction brakes (when you loose lots of energy) kick in when you are using the brake pedal? I.e. do you get pure regen at low g, just like with 'one pedal' driving, or do the friction brakes kick in straight away? The purpose of my question is to ask whether a high regen (one pedal driving) mode gives more regen than a low regen (coasting) mode used with the brake pedal? I.e. if you have to brake, then is it more efficient to be in a high regen mode than a low regen (with brake pedal use) mode?

Hi, I believe the accelerometer calibration controls the majority in when the brake lights are triggered. Perhaps you can dive into this a little bit further. Thanks for the channel. I look forward to more i3 videos. I have owned a 2014 for 3 1/2 years and I love it. Owned an ‘86 928 prior for 23 years. Don’t miss it. 😎

I cant turn regen off in my enyaq. I think its ace to have regen when you live in hilly areas like west yorks where i am.

It is poor anticipatory driving that is bad for range. With "One Pedal Driving" I consider the pedal as "progress Control" rather than on/off .. I very quickly learnt to feather the pedal for controlled smooth stopping - something I gleaned from towing with automatics

The headline is very misleading. It should read "Braking is Bad for Range" Whilst it is correct that regeneration doesn't recover 100% of your kinetic energy, using the brake pedal recovers 0%. So to get maximum range you should control your speed anticipating stops such that you don't need to use the brake pedal. Using the regenerative braking is very useful especially if you are descending a hill or slowing for any reason.

I've got a Nissan Leaf 40kWh and always drive in B (braking) mode and I'm a bit of a a hyper miler, consistently get better than average efficiency compared to others on the Nissan Leaf FB group, though the summer I've been averaging 5.4 miles/kWh, 700 mile round trip to Scotland and back in June I got 4.8 and I wasn't hanging about. Having been a driving instructor for almost 40 years I know that anticipation is the key to efficiency, even more so in an EV than an ICE car. I wonder if the i3 makes more regen the lower the battery %age is, I certainly find that in the Leaf, I like to keep the battery between 80% and 90% which gives the most balanced level of regen. Very rarely use the brakes at all.

Downhill , that’s the real winwin. So always you will have unpredictable situations, someone tailgating you, but yes you can of course aim to plan ahead to the point that regen is unnecessary. It’s very satisfying infact ! I like the quote ‘arrive to depart’ someone pointed out here. The idea that you are harming the battery … ha, I doubt it. The BMS on the i3 is very sophisticated. I doubt it’d allow any detrimental charging to occur. Thise track day pads , maybe try a caterham on track or a Lotus. You’ll do more than one track session on a set. And you’ll drive home safely. The Cayman is a fabulous machine. But it ain’t light, compared to an Elise. Of course, you may like roof that works effortlessly and hate squeaks… but if you haven’t tried a Lotus, you really really should ☺️

I agree, but how do you turn of the regen breaking?

The title is a bit misleading (I suspect intentionally but I’m good faith). ‘Regen is good for range but efficient driving is even better’ would be more accurate but less catchy.

Title seems like clickbait. Regen braking is more efficient than friction braking. You sort of get there in the end but you gloss over that the i3 communicates when it's at its most efficient: ePower meter at dead center. It's moving without taking any energy from the battery or losing any to braking. Probably anathema to you but in 8+ years of i3 driving, I've found ACC is significantly more efficient than my manual control. The computer keeps power use the neutral zone more often than I can.

Your theory is probably correct, but in practical driving situations regeneration will benefit you. Because you will break, and lose energy. Unless every other car and pedestrian has travelled abroad 😂

Note to commenters. Your car uses 'brakes' to stop . . . if your brakes 'break', you may need to take a 'break' and repair the 'brakes'.

LOL! Tremendous video. To do what you’re suggesting (in an i3 specifically is also not stop accelerating) Instead you’d need to balance the throttle to make sure the i3 doesn’t activate regen. The second you lift off completely the i3 will regen, you cannot turn this feature off entirely. So maximum range given your common sense physics is to not brake and not stop accelerating.

Making up an argument that isn’t there….

*clickbait*

Look Fannybaws I will explain the most important reason why regen is bad 1stly from a yr round point its too energy intense in the battery ie will severely shorten the battery ACTUAL life ie lifetime and secondly it should be 100% turned off between October and end of march (or at least turned to minimum if turning off not possible to turn actually off) for the reasons of brake corrision as if this was not bad enough as it is in the UK in normal cars it's 4x a problem in electric cars Soooo regardless of ANYTHING everyone with EV's make a very deliberate point of breaking very late at a decent speed (say approaching a junction or roundabout (obviously with no traffic behind) to help keep the brakes cleaned up and corrosion free......Psssst....Missed you princess......yes...it's me :)

Change the title of the video..