[121 Kw]

I know the app has plenty of short comings but is still a good tool, but I'm confused with a change in range it's giving me now. Does it look at weather?

I have a destination 165 miles away I've contemplated all summer driving too, there are zero chargers along the route. In summer the app would say I'd get there with ~15-20% charge remaining. Now it's regularly saying I would come up short, but as much as 10% but sometimes around 3%.

It also seems to give me a different number throughout the day even if I haven't moved my car in days. I assume it looks at recent driving behavior? Even adjusting the departure time did not seem to have an effect though spot checking though the day it would change.

The destination is within 300ft elevation of the starting location, though there are a few summits along the way. The speed limit is dominately 80mph on route, and I've heard that is factored in? If I take the car I'd probably set the cruise at 70mph and try to use minimal heat.

I just find the change strange and disconcerting as I was contemplating making the trip next week.

 

[Fivedoor]

Does the total drive time change as well as your energy consumption? I know with google maps, traffic conditions will affect your average speed as shown by the trip time. In your example above the average speed is 66.4 mph (166 / 2.5). If this app uses traffic conditions, AND there is heavy traffic / accident slowing down average speed that would reduce your projected energy consumption and put your destination within range. For example, If it shows 3 hours trip time this would mean your average speed was slowed down to 55 mph significantly reducing energy use.

Keith

 

[121 Kw]

Hmm. It's a pretty empty stretch of highway with no construction. Maybe a little bit leaving town around rush hours, but I can't see that first 20 miles adding 20% range.

I regularly make this drive in a company gas vehicle, only occasionally do I need to take a personal car. So I'm pretty familiar with the route conditions, just trying to figure out what changed in the app reporting and if I'm bold enough to ignore the recent estimates, particularly if I drive 10mph under the speed limit.

 

[Pike Bishop]

You might want to check the software with a slide rule; at least get some indicators that make sense.

Try this: You have a 166 mile run and want to dedicate 50kWh of your battery to get there. 50 kWh means your are conservative and are holding 10kWh in reserve. You have to exceed 3.3 mi/kWh to make the run with 50kWh. (divide miles by kWh).

• Is the software thinking you drive more aggressively than 3.3 mi/kWh?
• Have you exceeded 3.3 mi/kWh at a reasonable speed in other drives?

If the answers are OK, the drive should be no problem.

Also be creative on back ups. There is a new EA station at the WalMart in Fernley that cuts the charging station distance to 135 miles. https://www.plugshare.com/location/186879 I have found the Chevrolet Energy Assist app has delays in updating. If you leave Fernley with 80% charge (48kWh) you can still make Winnemucca with 8kWh in reserve if you exceed 3.4 mi/kWh.

As a real drop-dead option, there is a TA truck stop near Mill City with truck hookups. With a portable 240V charger you can easily add a few kWh.

 

[Fivedoor]

Hold up, just had a thought... are you always at 100% charge when you check this? The app knows the state of charge of the battery when it is making it's estimates.

Keith

 

[hickman55]

Try A Better route planner: https://abetterrouteplanner.com/?plan_uuid=140fffea-1dde-4ad2-8953-3f9ecb3a16b2

 

[121 Kw]

According to the Bolt I typically average 3.8-4.2 mi/kw so I cannot see it assuming 3.2 from my habits, but I could from the speed limits. The Fernley station would be useless driving out to Winnemucca because I'd still be near 90% charge.

I've charged the car to 100% exactly twice since I got it last May. Typically I keep it topped around 72% (which typically tells me I have 200 mile range), but as a test three days ago I bumped it to 90% and the results are the same in the app. I also played with battery level at departure and departure times to see their impacts. Setting at 100% is where it's still telling me I'll be short, even though a couple months ago it was saying 20% remaining.

I've definitely looked at the slide rule math, and the worse efficiency I've ever gotten on the highway was 3.2 going 75-80mph up in elevation. Using 60kw or 57kw and 3.2 still gets me there. Checking it right now says -4%, which is an astoundingly low 2.6mi/kw. I don't get it. All summer long it was using a reasonable 3.4 mi/kw even though that was below my daily average. Sure it's cooler out, but the highs are still in the mid-low 80's °F.

 

[surgeonFWW]

Hold up, just had a thought... are you always at 100% charge when you check this? The app knows the state of charge of the battery when it is making it's estimates.

Keith

I agree. Why would a Bolt EV think you could go less than 166 miles in the summertime, unless it thinks you can only use the energy that remains in the battery "at that time"?

 

[Pike Bishop]

Perhaps it would be useful to clarify the question we are trying to answer.

Are we trying to understand an algorithmic procedure in the My Chevrolet app, or drive to Winnemucca?

 

[redpoint5]

If it were me planning the trip, I'd do my best to do my own math, and if it looks pretty reasonable (which it seems it is), I'd just monitor my progress as I drove and see if adjustments are needed. Using more than expected, slow down a bit. Have plenty of extra left, speed up.

 

[121 Kw]

More so the algorithm of the app, because I wonder if I'm missing something that it knows and is forecasting?

The car tells me I should be able to make it based on my normal driving habits, but 100% highway is not my normal driving habit.

 

[redpoint5]

I don't know if the car has instantaneous consumption gauges, but I'd think you can test various speeds to see what the consumption will be, and people on here have already plotted those graphs.

If it were me, I'd choose faster travel than heater use, if those were my options. I would run the seat heater (which is extremely efficient) and just bundle up to whatever degree necessary. Heater use would only be used to keep fog off the windows. Then again, if it were me, I'd take the gasser if charging at the destination wasn't convenient.

Your question about how the app calculates range is a good one though, and I'd be curious to know what factors it considers.

 

[121 Kw]

It has a decent efficiency plot that can be watched in real time. My red dashed line moves between about 3.8-4.2 mi/kw. There are a few hills between home and work.

I just took these photos of mine. I think the bar on the right updates every mile then commits the 5-mile average to the chart on the left.

 

[Pike Bishop]

More so the algorithm of the app, because I wonder if I'm missing something that it knows and is forecasting?

The car tells me I should be able to make it based on my normal driving habits, but 100% highway is not my normal driving habit. View attachment 27286

Nice pictures, yet I would interpret them in a different way.

Your battery gauge is showing 80% with a resolution of 5%. That says you have at least 45kWh on board ((80-5)%*60kWh).

Projecting from history (which may or may not be useful for the future), the range estimate gives you 168 (low) or 205 (midpoint) estimates.

Compute the mi/kWh with the slide rule again...205 miles at 45kWh means an estimated consumption of 4.6 mi/kWh. Personally, I have not seen this efficiency on the highway. You are a very conservative city driver!

If you use the EPA efficiency of 3.9kWh/mile, you only have a 175.5 mile range to zero.

My feeling is the app is using the actual battery level and projecting based on EPA and speed corrections. The range meter is using the battery level and past driving history. They will not match up.

For your first drive to Winnemucca, start with direct measurements from known instruments and avoid computed, projected, or imputed ranges.

In order of trust and reliability, this is what I count on in my Bolt:

• The speedometer and odometer. GM has been measuing speed since 1922. These give you accurate distance and can be used for instantaneous consumption (see later).

• The kWh used on the main display. kWh is a direct measurement in a DC system. Use this to tally how much you have used.

• The instantaneous energy in kW on the main display. Divide speed by instantaneous energy to get mi/kWh. You should be able to estimate this in your head (60mph/15kW=4mi/kWh)

And yes, you will make it to Winnemucca. At 4.5 mi/kWh, you can probably drive via Gerlach and the Black Rock Desert...

 

[121 Kw]

I give up.... Says I'll make it now. Not sure what changed since yesterday....

(I'm at my office instead of house for the 4 additional miles)

 

[XJ12]

I give up.... Says I'll make it now. Not sure what changed since yesterday....

Wonder if wind is factored in?