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Hello from soon to be Kona driver from Denmark. Hopefully we receive it before summer.

In the meantime I have been watching a lot of youtube about the Kona and other EV's.

You often hear that a lot of things affects the consumption - like speed, temperature, heater/AC, incline aso. But how much?!?

I wanted to get a feel for how much each factor affects consumption.

I have made a website where you can drag sliders for speed, temperature aso. and see on a graph how it affects consumption. You can also see which elements adds to the expenditure and how much.
Eg. how much of the total consumption is because you are driving up an incline - or increased wind drag because it is cold and the air is denser.


I would be happy to get feedback from you - if you find it useful, have ideas for features or how to improve the model.

I plan to add more EVs to the model as I find their specs. I definitely want to get them for the Tesla Model 3 :)

Regards
Martin Nielsen

PS: I am realising how much speed matters and why you can hypermile :)

 

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Hypermiling is not necessarily about driving slowly, it is about 'managing your momentum' so it works for you as much as possible and works against you as little as possible.

Consider this and maybe we can discuss it more;- Getting that bit more range from donald-style driving.

I regret to say it is meaningless to talk about degrees of consumption when going up grades or with/against wind speed, in some cases it can even work for you by going up a hill if it means you can place your power draw into the middle of the efficiency spot, and then be able to coast down the other side at zero power. This would actually be more efficient than a completely flat steady speed, but if the grade is steeper then ... maybe not!

There are other scenarios like this too, where your 'immediate' consumption may be higher in 'Scenario A' than 'B' but your overall consumption is lower in 'A' than 'B' when you take into account the whole trip.
 

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Hi Donald
Thanks for you comment, and the way to think of the motor efficiency map as something to traverse choosing the best path possible. It makes me wan't to make a screen in the car that put a dot in real-time on where you are on the efficiency map :)

I regret bringing in the topic of hyper-miling as a last quick thought in regards to the evconsumption.mdn.dk site. The purpose of that page is to illustrate why, when driving, the car shows the instantaneous consumption it does. In that moment driving up an incline a part of the consumption is going to the increase in potential energy
 

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I decided to get an EV where the range means i dont need to care about this stuff, just the same as I don't with a ICE car (unless driving in East Sussex where petrol stations appear to be going out of fashion)
Should that not be the case with the Kona at around 400km range, in a small country?

Kudos for making a pretty graph but reading things like this is likely to have prospective EV users run to a "self charging" Toyota faster than you can say "nerd".
 

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Yep, it is great to be able to do many trips without having to charge en route.

There is still a point in getting knowledge to be able to understand why you are able to only drive 250 instead of 400 km between charges in one set of circumstances than others. Or why you expended double the amount of energy per km driven .

I thought this would be the right place to nerd about EV's but I gather that you would rather we choose the subjects to create good PR for EV usage and attract as many new user as possible?
 

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East Sussex where petrol stations appear to be going out of fashion
Good, good. :)

Actually maybe we should start logging the closures as a measure of the progress of the transition to EVs. Or will they reinvent themselves as charging, coffee, snacking and shopping stations?

I thought this would be the right place to nerd about EV's
You thought right. AnotherJoe's point is valid but it's just one aspect. Keep nerding, I say.
 

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Oh yes, you'll find lots of needs on here! Many of them have been thinking about all this stuff for years while struggling with small battery BEVs where it's all critical.

Most people hope to relax when they get a car with 200 miles range.

Have a look at the threads for the older vehicle types for everlasting debate on efficiency.

Sadly I can't help directly, not being that level of nerd myself.
 

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One technique that helps range is to not use the ring road bypass around the town you're approaching, but simply to drive straight through the middle! Journey is shorter so less power used, and speed tends to be lower so far less wind drag!
 

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I have made a website where you can drag sliders for speed, temperature aso. and see on a graph how it affects consumption. You can also see which elements adds to the expenditure and how much.
Eg. how much of the total consumption is because you are driving up an incline - or increased wind drag because it is cold and the air is denser.
It's a great model, Martin. One attribute I've been trying to identify is Kona regen efficiency, which is very impractical to measure accurately on the road, nearly impossible. I was trying to simulate this with your model by driving up, then down the same slope and noting the total power requirements.

It indicates a regen efficiency of effectively 100%, based on a typical scenario outlined below.

At a constant 40 km/h:
78.89 kW up 15% grade
then -59.95 kW down 15% grade
or 9.46 kW on the flat

So, if I drive for 1 hour uphill at 40 km/h I use 78.89 kWh, then 1 hour downhill at 40 km/h I recover 59.95 kWh, net usage 18.94 kWh.

If I drive for the same 2 hours on the flat at 40 km/h I use 2 x 9.46 = 18.94 kWh. So regen efficiency according to the model is 100%.

Breaking down the components, what I'm seeing is that transmission, DC/AC and battery losses do not increase as expected when there is a higher current. It seems that this is where the actual losses would reside in the climbing and descending situation, making regen efficiency less than 100%.
 

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It's a great model, Martin. One attribute I've been trying to identify is Kona regen efficiency, which is very impractical to measure accurately on the road, nearly impossible. I was trying to simulate this with your model by driving up, then down the same slope and noting the total power requirements.

It indicates a regen efficiency of effectively 100%, based on a typical scenario outlined below.

At a constant 40 km/h:
78.89 kW up 15% grade
then -59.95 kW down 15% grade
or 9.46 kW on the flat

So, if I drive for 1 hour uphill at 40 km/h I use 78.89 kWh, then 1 hour downhill at 40 km/h I recover 59.95 kWh, net usage 18.94 kWh.

If I drive for the same 2 hours on the flat at 40 km/h I use 2 x 9.46 = 18.94 kWh. So regen efficiency according to the model is 100%.

Breaking down the components, what I'm seeing is that transmission, DC/AC and battery losses do not increase as expected when there is a higher current. It seems that this is where the actual losses would reside in the climbing and descending situation, making regen efficiency less than 100%.
I am not sure how you are making that calculation but it is virtually impossible to get figures accurate enough to do it like you are saying.

The total conversion of gravitational energy of a 2 tonne car at 40km/h down a 15% grade is around 30kW. So you'd have to be going at least 80km/h or down a 30% grade to get 60kW.

If you were to require 9.46kW to run at a steady 40km/h that would mean your mi/kWh (sorry, I have to fall back into our imperial units to get a feel for this) is 2.6mi/kWh at a steady 25mph, which is way out.

You also need to define what you mean by 'efficiency'. Are you trying to get an estimate of the round trip efficiency of electrical energy into kinetic and gravitational energy and then back again, or simply from those (which you need, so you might be double counting otherwise) back into electrical energy?

You can bank on around 90% conversion of electrical energy from the battery to mechanical power, then the same back again with a further 85% efficiency stuffing that back into the battery. With other variables thrown in, temperature, the particular trajectory of motion through the efficiency map, etc, regen is around 60% 'efficient'.

As an absolute measure of energy, it become much less, and also less efficient, at slow speeds. It adds so little to regen below 10mph I wish they'd blend out regen to zero by 5mph so one can get a smooth stop. It is really clutching at straws to try to get electromagnetic deceleration down to 0mph and I have yet to drive an EV that does this perfectly, the best so far, by a good margin, was the Fluence. Everything else clonks, strains, lurches, changes the decel rate suddenly, or a combination of any or all of those.

If anyone who actually calibrates these things is reading, please blend brakes to 100% and regen to 0% by 5mph or less, thanks!!....
 
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