Question about idling in traffic

[butter]

Hi everybody,

Please note that I know nothing about the "how" behind electric vehicles.

So this is my question: would idling in hellish L.A. traffic for 2 hours over 25 miles affect the battery life of, say, the all-electric Aptera?

I want to know because that is probably the biggest enemy to driving in Los Angeles: the slow slow slow slow traffic.

Obviously, with gas-powered cars, gassing and braking and gassing and braking for 2 hours across 25 miles uses more gas than zipping across those same 25 miles in 25 quick minutes (which is more likely around 4 a.m.) (hence the delineation between city driving mpg and highway driving mpg).

Part of my agony while stuck in traffic is the wasting of my time -- but knowing this really can't be helped, it's not half-bad when you get used to it and have some form of entertainment in the car. What is a lot more agonizing to me is the wasting of the fuel.

So back to the question, just to reiterate: would stop-and-go traffic negatively affect the battery of an all-electric car, the way it does for a gas-powered one?

A related question: there is idling that involves slow travel (gas & brake, gas & brake), but there is also idling that involves sitting at the curb waiting for your dad to put his shoes on, find his wallet, grab his cell phone, give the dog one last kiss, and come out and hop in the car. If I know I'm going to be waiting in the car for somebody, I generally just turn the engine off, because I worry about the fumes being expelled as well as the usage of fuel while sitting there going nowhere.

Does this going-nowhere idling also affect electric cars?

Sorry if I'm being so repetitive.

Last question: I know as a layperson that for the Prius, braking isn't a complete waste of kinetic energy because of some thingy in there that turns the heat (or whatever is produced as a by-product of braking) into something that helps recharge the battery. You can correct the accuracy of my paraphrasing this, but all I know is that braking is in fact slightly productive for the Prius.

Would braking play a similar role in the Aptera? If so, would there be a difference between its effects on the hybrid and the all-electric (i.e., would the hybrid somehow derive more benefit from braking than the all-electric)?

Thanks a quadrillion for reading this and to all future replies!
Still excited as ALL HECK
Amy

[palmer_md]

Hi Amy,

The best thing about sitting stopped in an electric car is that you are not wasting any energy (except for was is used by the radio and the instrumentation lighting and such). The power used by the radio and instrumentation is almost nothing compared to a moving vehicle. You can just sit in the car with the radio on and feel confident that you are not wasting any energy.

Stop and go traffic is not going to hurt your range in an EV. In fact you will get better range in slow moving and stop and go LA freeway traffic than if the freeway were moving along at 65.

The Aptera will have regenerative braking to capture some of the energy used when stopping. Regenerative braking will capture the same amount of energy whether its the EV or the PHEV.

I hope this answers all the questions you had.

Michael

[butter]

Yes it does! Thank you, Michael! And thank you for replying in the succinct manner that eludes me.

Yay,
Amy

[butter]

Extra-credit question:

if I were waiting at the curb for my dad to come out and hop in the all-electric Aptera, would I be kinder to my car and the environment by:

1. idling for 5 minutes withe car on, or
2. turning the engine off, waiting with it off for 5 minutes, then turning it back on as soon as Dad showed up

Which is better/worse for the car and the environment?

Or is the difference almost negligible?

[KarenRei]

If you're not using the AC or anything, negligible (oh, and you get the outside air cooling, as opposed to AC, for free, since that's solar powered).

[davidrools]

Extra-credit question:

if I were waiting at the curb for my dad to come out and hop in the all-electric Aptera, would I be kinder to my car and the environment by:

1. idling for 5 minutes withe car on, or
2. turning the engine off, waiting with it off for 5 minutes, then turning it back on as soon as Dad showed up

Which is better/worse for the car and the environment?

Or is the difference almost negligible?

It's much better for the environment and negligibly better/worse for the car to shut it off for 5 minutes. Starting up a car after it's been off for less than an hour doesn't take up much extra fuel or cause much engine wear at all. In fact, I'll shut off my car if I just miss a green light and have to sit for 2-3 minutes. Of course I watch and anticipate the light change so I'm up and running for a few seconds before my light turns green.

[butter]

You do realize this question was about the all-electric version of the Aptera, right? (Not a regular gas-powered car) Just checking...

[davidrools]

I was replying to the "bonus question." The OP had pretty much been answered :)

[butter]

Both the original question and the bonus question were mine, and both were about the Aptera Typ-1e, and the reason I asked the bonus question was that I was aware of the answer for a gas-powered car -- which is what your answer sounded like, esp as it was contrary to KarenRei's answer to the bonus question -- and simply wondered what, if any, difference there would be if an Aptera were in the same situation.

I'm generally curious about how I might alter my driving style/habits once I get my paws on an all-electric vehicle, as certain problems with gas cars (such as using up gas while idling) wouldn't exist with the Aptera.

[LQUAN]

The good thing about electric car is that no energy is being use by the motor when you are not stepping on the gas pedal. Unlike your gas-powered car with automatic transmission, your electric car will not budge until you step on the gas pedal. It won't even budge when your foot is off the brake pedal, unless you are on a slope. Aptera does not have a transmission, only a rubber belt between the motor pulley and the wheel pulley.

[Dubito]

Seems like there should be another moniker for “gas pedal” in an electric car. Accelerator?

[davidrools]

[...]wondered what, if any, difference there would be if an Aptera were in the same situation.


Since the typ-1e is electric, it doesn't need to idle. So there's no difference in energy usage whether you're in "park" or just not moving (like in traffic). It's really quite different from what we're used to in conventional cars, and not very much like any appliance I can think of. Let me explain it like this:

Imagine there are two switches in the Aptera. One switch turns on all the interior electronics - radio, navigation, instrument panels, etc., and headlights if you need them. This one stays on all the time while you're in the car but uses very little energy.

Then imagine that the second switch is attached to your "gas" pedal. As soon as you press the pedal, it turns the switch "on" and makes the motor go. A soon as you let off the pedal, it turns the motor "off" (and then, by the way, kicks in the regenerative braking system). So every time you let off the gas pedal in traffic, you're essentially turning the "engine" off. (I put engine in quotation marks because it's not an engine but a motor)

Hope that helps!

Edit: to specifically answer your question, yes stopping in traffic will slightly decrease the range of your 1e as opposed to constantly moving. Realistically, traveling around 12.5 mph (your average speed on a 2 hour/25 mile commute) is probably near the most aerodynamically efficient speed to travel and you could probably go much farther on a charge than you would if you were cruising at 65mph.

[LQUAN]

A soon as you let off the pedal, it turns the motor "off" (and then, by the way, kicks in the regenerative braking system).

I thought that the regenerative braking system only kicks in only when you step on the brake pedal. When you let off the accelerator pedal while in motion, the wheel and motor rotor would free-wheeling on their rotational momentum. With the regenerative braking, Aptera does not need brake booster that runs on engine vaccuum like on gas-powered car. The electromagnetic force field creates by the regenerative system quickly slow down the motor rotor. Just my own 2cents.

[davidrools]

Regenerative braking can be designed either way. You're right that it can be set up to "free wheel" when off-throttle. I'm not sure how it will be designed in the Aptera. I know the Tesla roadster is designed to emulate engine braking as would be experienced when driving a manual transmission.

Regen will be tricky in the Aptera since you've only got one wheel, in the rear, to do the braking. This is not the ideal location to apply braking force. Especially when braking around a corner, too much regen/braking force on the rear wheel could cause loss of traction and oversteer. I wouldn't be surprised if they incorporated a steering angle sensor to reduce regenerative braking effect under tighter turns. If not then I need to submit a patent application ASAP!

[LQUAN]

Regenerative braking has some electromagnetic force to slow down the motor but it is not so powerful to stop the motor on a dime. The electromagnetic is strong at high speed but degrades as the motor slows down. Therefore, it only makes sense to apply regenerative brake when the driver steps on the brake - not when he/she lets off the accelerator pedal. Can you imaging letting off the accelerator and have the regenerative braking kicks in only at the rear wheel while make a sudden sharp turn with no brake applies! Yikes!:eek:

[davidrools]

The electromotive force under which regenerative braking operates is dependent on the load applied to the motor/generator, so the force can be modulated for however much regenerative braking force you want to achieve. Apply zero load to the motor and you'll freewheel. Apply a heavy load and you can lock up the wheels. You could even do that at low speed, but at that point you'll be using battery power to [I]stop the car. You're right that at high speed, more force CAN be applied through regen but that full force doesn't necessarily need to be applied. I imagine a system where, when you let off the gas pedal you slowly decelerate, and if you start to turn in, the regenerative braking force is decreased proportional to your speed, steering angle and yaw rate.

[LQUAN]

You are right. For certain conditions, your system is useful. But most of us want electric cars that operate similarly to our gas-powered cars. On long drive, once in a while, I like to take my foot off the accelerator for blood circulation or scratch my sole without having to slow down too much. Freewheeling when your foot is not on the accelerator is much much more efficient than having the accelerator ties to your foot. I don't want to use energy when my car is going down hill. I have a habit of "pulse and glide" to save gas :D .

[Dubito]

Don’t we think Aptera will have cruise control, or is that less efficient than an alert driver anticipating energy needs?