New IMiev testdrive in the US.

[Matthijs]

qfaJS_7ZaFA
Link for 16:9 view (http://www.youtube.com/watch?v=qfaJS_7ZaFA)

It seems plans are to introduce the iMiev in an updated model form to the states in 2010/2011. Note that the iMiev has a 2 mode drive program, "Eco" and normal mode. You can see the Imiev Southern California Edison version.

[butter]

Wow. Very nice. I want.

[KarenRei]

Hey Butter -- long time no see :) Too boring around the ol' Aptera Forum, are we? :)

[butter]

Hey Rei,

Yeah, up until last week's revamping of the official website, which produced some readable comments on these boards, I'd been pretty bowled over with boredom from the constant jabbering over the most minute of hypothetical details. It would almost be kinda funny if it weren't so incredibly... BORING. Heh. I don't know crap about crap, so it's not like I can get involved even if I wanted to. I'm an end-user, what can I say. Heheheheheheh...

xxoo

[n_dawg]

It seems like the "Brake" gear is rather redundant – if it has regenerative braking, wouldn't you just ride the brake pedal all the way down the hill? Certainly that's not advisable in an ICE car, but in an EV it shouldn't be a problem.

[NeilBlanchard]

Hi,

It depends on how the brake system balances regenerative braking with mechanical braking. The Prius has the same B setting on the transmission, and for really long downgrades, this makes sense. Also, you know that you are not using the mechanical brakes.

[KarenRei]

Meh... how hard is simply having the accelerator accelerate and the brake pedal brake (brake by wire, with as much energy from regen as is possible and safe)? I, like most people I've talked to, am not interested in having my car be wasteful in order to simulate an effect that I try to get rid of in my ICE car (engine braking). I dislike engine braking enough that, on the highway, I often shift to neutral when going downhill (yeah, the car burns gas idling, but less than I'd lose in the engine braking losses). I like the feel of "efficient", and having a vehicle slow down quickly when I let off the pedal simply doesn't feel efficient.

[NeilBlanchard]

Hi Karen,

I've been ecodriving for a while now; and I understand the different types of coasting.

The programing on the brake pedal is designed by the car maker -- the new Honda Insight has braking that uses more regenerative braking than the previous design.

http://world.honda.com/HDTV/news/2005-4050705b/

You're right about coasting: to ecodrive, you need to only go fast enough to coast to a stop (within reason, of course) and only use your brakes when you have to. But, when you have to slow down in an ICE vehicle, you should use the engine as much as possible, since this shuts off the fuel -- in most/all fuel injected cars, anyway. In an electric/hybrid vehicle, you would want to use the regenerative braking as much as possible, and the B mode on the transmission is great for this.

[palmer_md]

Meh... how hard is simply having the accelerator accelerate and the brake pedal brake (brake by wire, with as much energy from regen as is possible and safe)? I, like most people I've talked to, am not interested in having my car be wasteful in order to simulate an effect that I try to get rid of in my ICE car (engine braking). I dislike engine braking enough that, on the highway, I often shift to neutral when going downhill (yeah, the car burns gas idling, but less than I'd lose in the engine braking losses). I like the feel of "efficient", and having a vehicle slow down quickly when I let off the pedal simply doesn't feel efficient.

When I first started driving electric, it was a strange feeling. (My car does not have regeneration. I built my car 14 years ago before the components were affordable and reliable.) When I let off the accelerator and begin to slow for a stop sign or stop light, you get the feeling that the car just accelerated. It is very strange. Your brain is so used to the deceleration that when there is none, it feels like acceleration. It is something that you become accostomed to. Some of the newer EV's have a small amount of regen to replicate this slight slow down, the prius also has a small amount of regen for this purpose. It is not wasteful if you are trying to slow down for a stop sign, but if you are trying to pulse and glide then it might not be as efficient as pure coasting. I would like to see this regen when off the brake a settable value. If you could choose from several presets of regen, one setting being zero, that would be nice. Then you can set it to your personal driving taste. Even a single button to turn it on or off would be great.

As far as coasting down versus the small regen, I agree that an ICE is very wasteful, but the regen is fairly efficient when the pack is able to accept a charge, and any speed lost is captured as energy in the pack. Without this regen I find that the car will coast too fast and then you have to start using mechanical braking. That last statement is true for my car, but the Aptera can have a light touch of the brake pedal to start regen without mechanical braking, so I see your point, on hills it is better to have it off and let he driver decide whether to use regen via his/her foot.

How about this. If you let your foot off the accelerator below 30mph the car has a small regen. At speeds above 30mph the car will simply coast. This way the driver decides at normal road speeds, and when you are in town and your probably off the gas to slow down or stop not to just coast, the small regen comes into play.

Michael

[KarenRei]

I simply want no regen when I let off the accelerator. No need to get used to it; I should already be used to it, as I shift to neutral fairly frequently when coasting downhill on the highway. The part I wouldn't be used to would probably instead be the lightweight/aero design, which should lose speed a lot slower than my Saturn does in neutral. But I'd love to get used to that, as I love the feel of efficiency.

One thing I've found is that engine braking loads on different cars vary greatly. My '86 olds (my backup car) has a huge amount of engine braking in comparison to my Saturn. Its engine braking load at 25mph feels like the Saturn's at 60mph. Shift it into low gear at any significant speed and it feels like hitting a wall.

As for regen efficiency -- at least according to Tesla, it's generally roughly equivalent to the square of the normal efficiency (pack efficiency * drivetrain efficiency). Not exactly, since charging and regenerating are not the same as discharging and accelerating, but close. So, if you're in a li-ion EV with a 87% efficient drivetrain and a 97% efficient pack, your accelerating efficiency will be 84% and your regen efficiency will be 71%. But if you're in a PbA EV with an 87% efficient drivetrain and a 75% efficient pack, your accelerating efficiency will be 65% and your regen efficiency will be 43%.