Quantcast

EVs and altitude?

classic Classic list List threaded Threaded
8 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

EVs and altitude?

Electric Vehicle Discussion List mailing list
I think I saw a reference that every 1000' climb in elevation is about the
same as 4 miles on level ground.  Is that the general rule of thumb for
EV's?

Bob, WB4APR
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20170503/35bca999/attachment.htm>
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

(depends): 1000' elevation climb=4mi flat: EVs and altitude?

brucedp5


That 1k' climb = 4mi flat might be more tuned for when walking
https://en.wikipedia.org/wiki/Naismith%27s_rule
 (which is a slow efficient mode of transport)

Cyclists also try to understand the energy needed for a long ride
http://www.flacyclist.com/content/perf/compare_routes.html

A GM Spark EV driver found this amount of energy used when climbing
http://www.mychevysparkev.com/forum/viewtopic.php?p=15508


For me and my former (rip) very inefficient S-10 Blazer conversion EV, it took 3 times more energy to make a 2,100 foot elevation change over 7 miles, drawing 300A to average 30mph in 2nd gear (point of reference, to maintain my 4,400lb - 2 ton EV @55mph on a flat highway, I would draw on average 100A when fully charged).

I know this because I was validating my way to see if I could make to Santa Cruz from the SF South Bay, charge and make make the return trip back. The heavy EV did not have the hp for Hwy 17, so I used the slower but less demanding back roads route, see
https://goo.gl/maps/v75i8CmgFSU2

At Saratoga, I mooched a L1 charge (this was before they had formal L2 charging) at its 500' elevation.
http://www.saratogahistory.com/History/called_saratoga.htm
 I did this to top off my charge as a point of reference, so I could tell how much energy it would take to climb to the pass' summit.

Winding my way up Hwy 9 (Big Basin Way)
https://en.wikipedia.org/wiki/California_State_Route_9#Route_description

 to Skyline Blvd (Hwy 35)
http://www.mobileranger.com/blog/highway-35-saratoga-gap-unwraped/

 and pulling over at the top of the pass to stop at the Saratoga Gap rest area (a smallish parking lot with nil to see, but it is a trail head and a break from the twisty-turny climb to the gap). The elevation numbers (500' @Saratoga oldtown, 2600' @Gap pass) I confirmed using
http://www.topozone.com/california/santa-cruz-ca/gap/saratoga-gap/

I opened the hood and let the air-cooled C600 controller cool down (it was hotter than a pistol but, solid as a rock, BTW cntrl co. is defunct). After letting the pack rest for a short while (to let the pack surface voltage rise), I took my readings.

I came to the conclusion that 3 times the energy was used by my heavy Blazer EV to climb that elevation change at that speed. So, the 7mi distance was like driving 21+ miles @55mph on flat Hwy 101.

Having accomplished that achievement, that led to many an EV adventure, pushing my EV driving-range envelope, long before there was the public EVSE infrastructure we have today in the SF bay area.

I not only got to make it the Santa Cruz wharf
https://goo.gl/maps/ykkpSASB17N2

but other places like Alice's Restaurant
https://goo.gl/maps/RVRSVWnByyx

 (imagine showing up with cord in hand asking to plug while I waited for my food?)
http://www.alicesrestaurant.com/

Though they had plenty of power, they had a large power panel set up just for music bands that would come play there using 120VAC and 240VAC outlets which I could have easily adapted to, they turned me down (EVs were just too new for them to grasp the concept). The food was good though.

I've had plenty of good times with that Blazer EV ... I still miss it  ::sniff::




For EVLN EV-newswire posts use:
http://evdl.org/evln/


{brucedp.neocities.org}
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: EVs and altitude?

Electric Vehicle Discussion List mailing list
In reply to this post by Electric Vehicle Discussion List mailing list
From a Physics perspective, adding elevation increases your potential
energy (which comes out of the battery in an EV)
Which you gain back upon descent.
Formula: Ep = mgh
In Earth's gravitational field, near earth the g = 9.81
m is mass in kg
h is height in meters.

So, using some random rounded numbers (fill in your own favorites and
repeat):
m = 2,000 (4400 lbs truck)
h = 300 (almost 1000 ft as was the question)
and let's assume it is a pickup truck, so it needs about 350 Wh per mi,
so 4 mi equates to 1.4 kWh of energy.

Ep = 2,000 x 9.81 x 300 ~ 6M (rounding 9.81 to 10 we get 6 million)
Joules.
One Joule is equivalent to one Watt-second.
So, one Watt-hour is 3600 Joules (since there are that many seconds in
an hour)
6M / 3600 = 1,667 Wh = 1.7 kWh

Indeed, an elevation gain of 1,000 ft (~300 meters) for a 4,400 lbs
truck costs at least as much energy as going 4 miles on flat road.
In fact, for the relatively heavy truck it is even over 5 miles.
For a lighter car, the amount of energy invested in elevation change
might be less.

NOTE that this energy is *on top of* the distance you'd need to drive to
get this elevation change.
So, if you take this truck, drive 3 miles to gain 1,000 ft then the
battery SoC would look as if you had done 3 + 5 = 8 miles.
And, you might need to account for higher losses in the components at
higher power level as well, but that is a secondary effect.

If you turn that truck around to go down 1,000 ft in 3 miles, the
battery will be re-charged with the difference between
The 3 miles you are driving and the 5 miles of range you are
recouperating from the height change, so your SoC should
Regain 3 + -5 = -2 miles. As a result, the SoC is showing the total of 8
+ -2 = 6 miles after driving 3 miles up and 3 miles down
And ending up at the same height as you started. Laws of Physics still
intact.
Hope this clarifies,
Cor.

-----Original Message-----
From: EV [mailto:[hidden email]] On Behalf Of Robert Bruninga
via EV
Sent: Wednesday, May 03, 2017 8:06 PM
To: Electric Vehicle Discussion List
Subject: [EVDL] EVs and altitude?

I think I saw a reference that every 1000' climb in elevation is about
the same as 4 miles on level ground.  Is that the general rule of thumb
for EV's?

Bob, WB4APR
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20170503/35bc
a999/attachment.htm>
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag
racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: EVs and altitude?

Electric Vehicle Discussion List mailing list
On Thu May 04 15:17:46 PDT 2017 [hidden email] said:
>If you turn that truck around to go down 1,000 ft in 3 miles, the
>battery will be re-charged with the difference between

But only if you have 100% efficient regen.



--

Bobcats and Cougars, oh my!  http://john.casadelgato.com/Pets
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: EVs and altitude?

Electric Vehicle Discussion List mailing list
On 4 May 2017 at 15:28, John Lussmyer via EV wrote:

> But only if you have 100% efficient regen.

Obviously you're not going to get 100% efficient regen, but you'd be
surprised how close you can get under the right conditions in a well
designed real world vehicle.  

I've posted about this in the past, but here it is again:

http://www.evdl.org/pages/evergreen.html

Axel Krause of Brusa drove his EV over the Swiss Alps in 1997.  The graph on
the page above is a little confusing; what it shows is the deviation of the
car's amp-hour counter from what he usually got in similar driving on flat
ground.  You can see that by the end of the trip, the amp-hours logged were
right back to what they'd normally be for a trip of that length taken on the
flat.

The gist of it is this: thanks to the drive system's regeneration, almost
all the extra energy he used going up the mountain, he got back on the way
down.

(No doubt this wouldn't have worked as well if he'd started out the trip
with a descent.  With the battery already full, there'd be nowhere to store
the kinetic energy.)

On the average his outbound trip (Gams to Stabio) used 10.7kWh / 100km.  
That's a more-than-respectable 173 Wh/mi.  It's also from the mains, not
just from the battery, so it includes the charger efficiency.  Not bad.

His average speed was 66km/h, or about 41mph.  

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Note: mail sent to "evpost" and "etpost" addresses will not
reach me.  To send a private message, please obtain my
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: EVs and altitude?

Electric Vehicle Discussion List mailing list
Early Leafs (2011 and 2012 model years) have the ability to select that
charging always stops at 80%.
I always use this to reduce stress on the battery in daily use as I do
not need the maximum range in daily use,
But this 80% charge has also been billed as a benefit for people who
live "on top of the hill" to allow them
To catch the regen energy when they descend from their home at the start
of the day and their trip.

Unfortunately, the EPA decided to average the 80 and 100% charge range
(which makes no sense)
To qualify the Leaf, so it has an arbitrary shorter range than its
actual battery capacity and therefor,
Nissan decided to remove the ability of the Leaf to charge to 80% on
later model years.
Cor.

-----Original Message-----
From: EV [mailto:[hidden email]] On Behalf Of EVDL
Administrator via EV
Sent: Thursday, May 04, 2017 10:48 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] EVs and altitude?

On 4 May 2017 at 15:28, John Lussmyer via EV wrote:

> But only if you have 100% efficient regen.

Obviously you're not going to get 100% efficient regen, but you'd be
surprised how close you can get under the right conditions in a well
designed real world vehicle.  

I've posted about this in the past, but here it is again:

http://www.evdl.org/pages/evergreen.html

Axel Krause of Brusa drove his EV over the Swiss Alps in 1997.  The
graph on the page above is a little confusing; what it shows is the
deviation of the car's amp-hour counter from what he usually got in
similar driving on flat ground.  You can see that by the end of the
trip, the amp-hours logged were right back to what they'd normally be
for a trip of that length taken on the flat.

The gist of it is this: thanks to the drive system's regeneration,
almost all the extra energy he used going up the mountain, he got back
on the way down.

(No doubt this wouldn't have worked as well if he'd started out the trip
with a descent.  With the battery already full, there'd be nowhere to
store the kinetic energy.)

On the average his outbound trip (Gams to Stabio) used 10.7kWh / 100km.

That's a more-than-respectable 173 Wh/mi.  It's also from the mains, not
just from the battery, so it includes the charger efficiency.  Not bad.

His average speed was 66km/h, or about 41mph.  

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL
Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = =
= = = = = = = = = = = =
Note: mail sent to "evpost" and "etpost" addresses will not reach me.
To send a private message, please obtain my email address from the
webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag
racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: EVs and altitude?

Electric Vehicle Discussion List mailing list
In reply to this post by Electric Vehicle Discussion List mailing list
That depends are the vehicles ability to regenerate as well. I believe my miev will only regen at 100 amps but I could burn more than 100 amps going up depending on my speed.

Sent from my iPhone

> On May 4, 2017, at 5:17 PM, Cor van de Water via EV <[hidden email]> wrote:
>
> From a Physics perspective, adding elevation increases your potential
> energy (which comes out of the battery in an EV)
> Which you gain back upon descent.
> Formula: Ep = mgh
> In Earth's gravitational field, near earth the g = 9.81
> m is mass in kg
> h is height in meters.
>
> So, using some random rounded numbers (fill in your own favorites and
> repeat):
> m = 2,000 (4400 lbs truck)
> h = 300 (almost 1000 ft as was the question)
> and let's assume it is a pickup truck, so it needs about 350 Wh per mi,
> so 4 mi equates to 1.4 kWh of energy.
>
> Ep = 2,000 x 9.81 x 300 ~ 6M (rounding 9.81 to 10 we get 6 million)
> Joules.
> One Joule is equivalent to one Watt-second.
> So, one Watt-hour is 3600 Joules (since there are that many seconds in
> an hour)
> 6M / 3600 = 1,667 Wh = 1.7 kWh
>
> Indeed, an elevation gain of 1,000 ft (~300 meters) for a 4,400 lbs
> truck costs at least as much energy as going 4 miles on flat road.
> In fact, for the relatively heavy truck it is even over 5 miles.
> For a lighter car, the amount of energy invested in elevation change
> might be less.
>
> NOTE that this energy is *on top of* the distance you'd need to drive to
> get this elevation change.
> So, if you take this truck, drive 3 miles to gain 1,000 ft then the
> battery SoC would look as if you had done 3 + 5 = 8 miles.
> And, you might need to account for higher losses in the components at
> higher power level as well, but that is a secondary effect.
>
> If you turn that truck around to go down 1,000 ft in 3 miles, the
> battery will be re-charged with the difference between
> The 3 miles you are driving and the 5 miles of range you are
> recouperating from the height change, so your SoC should
> Regain 3 + -5 = -2 miles. As a result, the SoC is showing the total of 8
> + -2 = 6 miles after driving 3 miles up and 3 miles down
> And ending up at the same height as you started. Laws of Physics still
> intact.
> Hope this clarifies,
> Cor.
>
> -----Original Message-----
> From: EV [mailto:[hidden email]] On Behalf Of Robert Bruninga
> via EV
> Sent: Wednesday, May 03, 2017 8:06 PM
> To: Electric Vehicle Discussion List
> Subject: [EVDL] EVs and altitude?
>
> I think I saw a reference that every 1000' climb in elevation is about
> the same as 4 miles on level ground.  Is that the general rule of thumb
> for EV's?
>
> Bob, WB4APR
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20170503/35bc
> a999/attachment.htm>
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag
> racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Read EVAngel's EV News at http://evdl.org/evln/
> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>

_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: EVs and altitude?

Electric Vehicle Discussion List mailing list


On 05/06/2017 07:00 AM, paul dove via EV wrote:
> That depends are the vehicles ability to regenerate as well. I believe my miev will only regen at 100 amps but I could burn more than 100 amps going up depending on my speed.

More relevant is whether the regen will slow you enough.  Or will you be
forced to resort to friction braking.  I don't live in hilly country but
I haven't seen a slope that max regen would result in increasing speed.

I've done some conservative regen tow charging with an imiev.  I chose
the mid level regen for about 50 mph towing which gave me mid-level
regen power.  That resulted in an increase of about 50 miles of range in
about 30 miles of towing.

_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Loading...