# Re: [EVDL] EVs and altitude?

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 <ev@lists.evdl.org> 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:ev-boun...@lists.evdl.org] 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
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