Mountain Driving: Range decrease for elevation gain?

[Anonymous]

For Mountain driving, what decrease in range, or % of battery capacity, would be expected for each 1000 feet elevation gain?
I would like to drive up to 6000 ft. elevation, if not 8000 ft elevation.
Yes, I know, I would regain most of the range (battery capacity) by regen braking going back down, but the question is whether the car would get up to a high elevation.

Also, for descending a long grade, if the battery becomes "full" , what does the car do then? Does it just use brakes to slow down for the remainder of the descent? (if, for example, I had recharged at the top of the grade)

I am considering buying a Bolt, but would like to be able to take it up into local mountains.
Otherwise, Ford C-Max Energi is a strong contender.
This would be my only car.

 

[SparkE]

For Mountain driving, what decrease in range, or % of battery capacity, would be expected for each 1000 feet elevation gain?
I would like to drive up to 6000 ft. elevation, if not 8000 ft elevation.
Yes, I know, I would regain most of the range (battery capacity) by regen braking going back down, but the question is whether the car would get up to a high elevation.

Also, for descending a long grade, if the battery becomes "full" , what does the car do then? Does it just use brakes to slow down for the remainder of the descent? (if, for example, I had recharged at the top of the grade)

I am considering buying a Bolt, but would like to be able to take it up into local mountains.
Otherwise, Ford C-Max Energi is a strong contender.
This would be my only car.

I have seen elsewhere the estimate of : 1.5kWh per 1,000 feet of climbing plus .75kWh per 1,000 of descending and reclimbing (independently, or 'in addition to', the mileage driven or electricity used to heat the vehicle).

Given that, it would take around 15 kWh to climb 10,000 feet. If you drove 100 miles getting to the top, you'd probably use 25-35 kWh for the distance covered, and more if you ran the heater or A/C. So maybe 35-45 kWh on the way up the mountain(s) (and lot, LOT less on the way down).

 

[Anonymous]

Thank you.
I'm hoping other users will tell us about their experiences.

 

[mbepic]

I'm also interested in what occurs when you have turned off Hilltop Reserve mode but you end up going down a steep hill; does that 'regen' energy just vanish, cause any battery problems, degrade the system???

 

[mikegrb]

It just doesn't regen and you use the mechanical breaks like a traditional ICE car. Perhaps not quite like a traditional ICE as you don't have the engine to downshift and help.

 

[gbobman]

There is still some braking done by the drivetrain, even enough to stop the car. Is isn't as much as when regen is available but it is still considerable. Even when I do a full charge (once a month) I still rarely have to use the brakes - but I still use them a bit more at those times.

 

[GetOffYourGas]

I have seen elsewhere the estimate of : 1.5kWh per 1,000 feet of climbing plus .75kWh per 1,000 of descending and reclimbing (independently, or 'in addition to', the mileage driven or electricity used to heat the vehicle).

I have found this to be a good estimate of energy use in my Leaf. The Bolt is similar in weight, so it should be roughly the same.

The CMax Energi PHEV is the best hybrid I've ever driven. It allows short trips in EV mode, but mostly functions like an amped-up (pardon the pun) hybrid. If you are looking for an efficient vehicle and have short daily drives, it will be a good fit for you. If you are looking to maximize the EV experience, you may be frustrated and/or disappointed.

 

[BoltEV17]

Potential Energy = m * g * h

m = 1,615 kg
g = 9.81 m/s/s
h = 304.8 m

PE = 1615 * 9.81 * 304.8 = 4,828,992 Joules = 1.341 kW*hr

At 90% efficiency it would take 1.5 kW*hr of energy to produce 1.341 kW*hr required to elevate the mass of the car 1,000 feet.

 

[sparkyps]

Potential Energy = m * g * h

m = 1,615 kg
g = 9.81 m/s/s
h = 304.8 m

PE = 1615 * 9.81 * 304.8 = 4,828,992 Joules = 1.341 kW*hr

At 90% efficiency it would take 1.5 kW*hr of energy to produce 1.341 kW*hr required to elevate the mass of the car 1,000 feet.

Or if you like to start with pounds and feet.
To life a 3700 lb car (Bolt with passenger) 1000 ft requires 3800 x 1000 x 3.766161⋅10-7 kWh

To lift one pound one foot requires 1 foot-pound of energy and 1 foot-pound of energy equals 3.7661609675872⋅10-7 kWh

My personal experience driving up 1800 ft of elevation on a 35 mile commute and back in the evening is my Spark EV converted all of it's potential energy on the way back down with 100% efficiency because I didn't have to brake. So driving up a hill and back down was the same as covering the same distance on flat ground. That only works if the slope is low enough that you don't have to brake to maintain speed.

Edit: And BoltEV17 correctly points out that you need to account for the efficiency of converting battery power to power at the wheels.