[Sequimbay]

My Lady and I took a little trip to our local Olympic National Park, and drove up Hurricane Ridge to the top of the mountain at 5,242 feet. It's a very steep climb, sea level to almost a mile high in 19 miles. That's a lot of up.
Soooo, we were at the toll booth for the park, appx a third of the way up, and had 12.4 miles left to the top. My Lady says " we're only showing 84 miles of range on the GOM, (Guess'o Meter) we won't make it to the top and back home".
I told her the car would regenerate voltage as we go back down, but was wondering what the percentage of loss would be.
So we went to the top, starting with 85 miles of range, and used 40 KW to go the 12.4 miles to the top. Slurp! Very steep.
GOM was now showing 45, so started back down in Low, so not to miss one micro-volt of charge, and arrived at the Toll Booth with 78 miles of range showing.
We used 40 KW going up and regenerated 33 KW coming back down. I get 82.5% of regen, or 17.5% of loss from what was used going up. However you want to look at it.
Any one else done any studies on what you get back from regeneration. Is my 82.5% recapture of energy spent going up and down a hill consistent with what you guys get?

Go to:
Visiting Hurricane Ridge - Olympic National Park (U.S. National Park Service)
for a look at the place. Worth a visit (in the summer!).

 

[Packard V8]

Yes, No, Maybe. Speed has everything to do with it. You were descending a curvy, slow speed road. Coming down from the summit of Haleakala National Park or down Pikes Peak would be similar percentage regen. However, coming down from Park City to Salt Lake City is a three and four lane expressway where it's dangerous not to stay out of the way of trucks running 70-80 MPH down the mountain. If one could safely stay in the right lane at 45 MPH, regen might match your percentage. The wind resistance from keeping up with 70-80 MPH traffic drastically drops regen percentage.

jack vines

 

[SpaceCar]

You can’t get a free lunch. Energy in will never full equal energy out. There will always be losses due to heat and other factors. With that being said an 82ish% return is not bad. I haven’t run an experiment to see but would use an OBD to collect data instead of the GOM.

 

[Sequimbay]

Agree with "SpaceCar" on the no free lunch, and speed, altitude density, wind, temp, wet or dry roads, and the temperament of your traveling companion can effect your % of regen on any up and down "mountain" cycle.
I'll go back up the mountain in a couple weeks and use my Innova 1000 OBD mobile app scanner.
Haven't used this on the Bolt yet, so it will be interesting to see what parameters of data relevant to the EV will be revealed. If any. Might have to use the On Star app or My Chevrolet app for that.

 

[martinknutson]

Yes, No, Maybe. Speed has everything to do with it. You were descending a curvy, slow speed road. Coming down from the summit of Haleakala National Park or down Pikes Peak would be similar percentage regen. However, coming down from Park City to Salt Lake City is a three and four lane expressway where it's dangerous not to stay out of the way of trucks running 70-80 MPH down the mountain. If one could safely stay in the right lane at 45 MPH, regen might match your percentage. The wind resistance from keeping up with 70-80 MPH traffic drastically drops regen percentage.

jack vines

This. You're overcoming air resistance in both directions, which can increase with the square of velocity. At lower speed, this tax is much smaller, but in no case does it increase your potential energy, which is what you're getting back in regen on they way down.

 

[Voldar]

The rule of thumb is about 65% recuperation of energy going down, in a normal driving.
The hardest acceleration is about 150 kW (160 kW seen in certain conditions) and max regen is 75 kW. That's about 50% losses. Now, you don't always use the 150 kW to move from A to B but depending on situations, you can regen 75 kW from B to A.
The beauty of an EV is that after a long steep descent, your brakes are cold, not hot like in the case of an ICEV.

 

[Sean Nelson]

The rule of thumb is about 65% recuperation of energy going down, in a normal driving.

That's exactly what I do based on my experience here in mountainous British Columbia. "2/3" is a nice easy mental calculation.

 

[lgbigfoot]

My Lady and I took a little trip to our local Olympic National Park, and drove up Hurricane Ridge to the top of the mountain at 5,242 feet. It's a very steep climb, sea level to almost a mile high in 19 miles. That's a lot of up.
Soooo, we were at the toll booth for the park, appx a third of the way up, and had 12.4 miles left to the top. My Lady says " we're only showing 84 miles of range on the GOM, (Guess'o Meter) we won't make it to the top and back home".
I told her the car would regenerate voltage as we go back down, but was wondering what the percentage of loss would be.
So we went to the top, starting with 85 miles of range, and used 40 KW to go the 12.4 miles to the top. Slurp! Very steep.
GOM was now showing 45, so started back down in Low, so not to miss one micro-volt of charge, and arrived at the Toll Booth with 78 miles of range showing.
We used 40 KW going up and regenerated 33 KW coming back down. I get 82.5% of regen, or 17.5% of loss from what was used going up. However you want to look at it.
Any one else done any studies on what you get back from regeneration. Is my 82.5% recapture of energy spent going up and down a hill consistent with what you guys get?

Go to:
Visiting Hurricane Ridge - Olympic National Park (U.S. National Park Service)
for a look at the place. Worth a visit (in the summer!).

I am curious. I take delivery on my Bolt soon and I have a friend who lives at the top of a very steep mountain. How did the Bolt do going up? Was it like a turtle? Was the struggle pretty hardcore? My Volt handles it like a charm. (I usually put in hold mode and use the gas engine)....

 

[NortonCommando]

... How did the Bolt do going up? Was it like a turtle? Was the struggle pretty hardcore? ...

You always have 200HP on tap. What do you think?
It's not like it loses power with the thin air like a gasser.

 

[The Other Tom]

Is my 82.5% recapture of energy spent going up and down a hill consistent with what you guys get?

I've never seen that much. Discharging at 40kW and recharging (regen) at 33kW is pretty strong. It must've been a steep hill!
I think the 33kW regen is so high because your battery was low. As you know, charge rate decreases as your battery fills up, so my guess is 33kW is not sustainable.

 

[ARob]

My Lady and I took a little trip to our local Olympic National Park, and drove up Hurricane Ridge to the top of the mountain at 5,242 feet. It's a very steep climb, sea level to almost a mile high in 19 miles. That's a lot of up.
Soooo, we were at the toll booth for the park, appx a third of the way up, and had 12.4 miles left to the top. My Lady says " we're only showing 84 miles of range on the GOM, (Guess'o Meter) we won't make it to the top and back home".
I told her the car would regenerate voltage as we go back down, but was wondering what the percentage of loss would be.
So we went to the top, starting with 85 miles of range, and used 40 KW to go the 12.4 miles to the top. Slurp! Very steep.
GOM was now showing 45, so started back down in Low, so not to miss one micro-volt of charge, and arrived at the Toll Booth with 78 miles of range showing.
We used 40 KW going up and regenerated 33 KW coming back down. I get 82.5% of regen, or 17.5% of loss from what was used going up. However you want to look at it.
Any one else done any studies on what you get back from regeneration. Is my 82.5% recapture of energy spent going up and down a hill consistent with what you guys get?

A few facts are questionable... you started with 85 miles of range, that implies you had ~ 21 to 28 kWh in the pack when you started the ascent (based on 3-4 mi/kWh efficiency). When you arrived back at the toll booth, you had 78 miles on the GOM, 7 miles less than when you started, so no way you regenerated 33kWh coming down. The way the GOM works, the most recent part of the trip weighs heavier on the range estimate, so you likely had a net negative total kWh consumed round trip. Doubtful you actually recovered more than 75% of the energy used reaching the summit.

kW are instant energy, kWh are the capacity stored in the pack.

There is no question regen is fantastic on long, downhill stretches. Once while returning to Denver from W Colorado, we hit the Eisenhower Tunnel (over 11K feet) with 55 miles remaining on the GOM and about 100 miles to reach home. Traffic was slow (typical for weekend return traffic from the mountain resorts), we probably averaged 15-20 MPH, but it was all downhill so when we reached Denver (5200 FT), we had added close to 90 miles of range, and 4 kWh of energy to the pack. We made it home, no sweat. Gotta love gravity charging!

Our club tries to do a Pikes Peak run annually, Bolts are among the best in terms of net energy used, but we typically use a few kWh round trip, no way regen replaces 100% of the energy used to reach the summit.

 

[lgbigfoot]

You always have 200HP on tap. What do you think?
It's not like it loses power with the thin air like a gasser.

Kind of what I was thinking. Except in a FB group someone posted that her vehicle really struggled and she thought she wouldn't make it. I was a little startled to hear that. Maybe it was gaslighting or something. Those groups sometimes do get people crawling in.. disguised as an EV lover but really a gasshole.

 

[Sequimbay]

Going up to Hurricane Ridge above Port Angeles, our 2018 LT2 zipped right on up. IN fact, I put it in cruise both ways, up and down, as it is a National Park and speeding tickets are no fun from a Park Ranger. Never a hint of struggle going up. There has never been a lack of power on any steep hill while driving either of my Bolts.
It starts out at 45mph speed limit, and the last 12.4 miles is at 35mph. I was amazed how the car kept to the exact speed on the way down, all the way showing a huge amount of regeneration.
I now own a 2023 Bolt LT1 EV(a gift from GM), and as soon as there is no ice and snow on Hurricaine Ridge, I'll go at this "Regen Challange" to prove to "Arob" that it did or did not regen 33KWH coming down the 11.2% grade. Inquiring minds need to know. I'll take GOM pix and post.
I think what might make this hill produce so much regen is the slow speed limits, the smooth asphalt road in the Nat Park, and the the 11.2% grade. Not fast enough to create wind drag, and light traffic.

 

[p7wang]

A few facts are questionable... you started with 85 miles of range, that implies you had ~ 21 to 28 kWh in the pack when you started the ascent (based on 3-4 mi/kWh efficiency). When you arrived back at the toll booth, you had 78 miles on the GOM, 7 miles less than when you started, so no way you regenerated 33kWh coming down. The way the GOM works, the most recent part of the trip weighs heavier on the range estimate, so you likely had a net negative total kWh consumed round trip. Doubtful you actually recovered more than 75% of the energy used reaching the summit.

kW are instant energy, kWh are the capacity stored in the pack.

There is no question regen is fantastic on long, downhill stretches. Once while returning to Denver from W Colorado, we hit the Eisenhower Tunnel (over 11K feet) with 55 miles remaining on the GOM and about 100 miles to reach home. Traffic was slow (typical for weekend return traffic from the mountain resorts), we probably averaged 15-20 MPH, but it was all downhill so when we reached Denver (5200 FT), we had added close to 90 miles of range, and 4 kWh of energy to the pack. We made it home, no sweat. Gotta love gravity charging!

Our club tries to do a Pikes Peak run annually, Bolts are among the best in terms of net energy used, but we typically use a few kWh round trip, no way regen replaces 100% of the energy used to reach the summit.

Correct, one should check Energy Assist (or via OBD2) for the actual SOC %.

 

[Sequimbay]

Will do that next time I go up, up, and away!

 

[GJETSON]

I am curious. I take delivery on my Bolt soon and I have a friend who lives at the top of a very steep mountain. How did the Bolt do going up? Was it like a turtle? Was the struggle pretty hardcore? My Volt handles it like a charm. (I usually put in hold mode and use the gas engine)....

Our 2017 can roll 92 mph up a steep mountain ascent. It doesn't even notice grades, except on the energy consumption screen.