Appreciation post: improved range

[Klinkman]

Gravity GT, 22/23" wheels, 3000 mi. I drive a ~400 mi round trip a couple times a month. 75% highway driving the other 25% of that is two lane mountain roads up and over multiple passes. This is Bay Area and coastal northern California, so we're not getting into crazy cold temps. Normal climate settings, and a do run the seat massagers on the last maybe 1/4 of those rides. I also like to ensure my tire pressures are 44 psi cold.

It used to take 66% of my charge to complete the trip, maybe ~2.35 mi/kWh if I recall correctly.

Now it takes 60% of the battery, and I finished the trip yesterday at 2.88 mi/wWh. Not complaining, this is a very nice surprise! Anyone have any idea why the mileage improved so dramatically all the sudden? It seems like somewhere in the last few hundred miles it just jumped.

 

[raleighone]

When released, they were saying it takes 2,000 or so miles for the car to adjust and give accurate mileage estimates. Maybe that's what happened?

 

[Klinkman]

When released, they were saying it takes 2,000 or so miles for the car to adjust and give accurate mileage estimates. Maybe that's what happened?

great, I hadn't head that "adjust for accurate mileage" thing before, thanks. So are you saying it was delivering that level of efficiency already?

 

[raleighone]

?...perhaps others here know. I'm not sure if the car is learning to be more efficient OR and more likely, the batteries start communicating more accurately after they've been "broken in" and used a bit...but I'm guessing.

 

[RandomDesign]

What the manual says is:

Efficiency is suboptimal during the early life of the vehicle (approximately the first 2000 miles of driving).

My guess is that it's likely a mix of both.

 

[johnse]

My guess is that mechanical systems are also wearing in. Somewhat equivalent to the initial break in period for engines.

 

[Saksak]

My guess is that mechanical systems are also wearing in. Somewhat equivalent to the initial break in period for engines.

Maybe!

I’ve also noticed a steady efficiency increase. I have stats on my morning commute. On the exact same drive of 20.8 miles over the last month:

Configuration: GDE, 7-seat, 20/21 wheels, smooth, DDP on highway, odometer at 1812 miles, trip meter stats.

• Mon Jan 05: 3.39 mi/kWh
• Mon Jan 12: 3.38 mi/kWh, 41F
• Tue Jan 20: 3.59 mi/kWh, 49F
• Tue Jan 27: 3.53 mi/kWh, 44F
• Fri Jan 30: 3.88 mi/kWh, 49F (no idea why this is so good)

Note: this is the better leg of my commute with consistent traffic conditions.. The return leg is worse but traffic conditions vary quite a bit. Avg round trip is around ~3 mi/kWh.

Two other factors that I can think of for the improved efficiency (in addition to mechanical systems breaking in).

1. Charge loss (battery degradation) through formation/growth of SEI. This is why Lucid is saying you’ll get better range after 2k miles, although 2k isn’t a magic number. This charge loss is rapid for a new battery then slows down over time.
2. Temperatures have been gradually increasing. Nights are not as cold, so battery starts out warmer (although I park in my garage).

I have a month’s worth of data that I’ll crunch through when I get a chance. I’m curious as to how charge loss through SEI shows up in the data. @Cyp The Eastern Edge - NotchEV edition race may have provided a data point (maybe Tom would be interested since he has the numbers in his StateOfCharge video). At the end of the race, available charge went from 8% to 0% when the Gravity finally got to sit and rest. I wonder if that is the BMS adjusting for 2k miles of SEI (at least, as one factor). I imagine it’s impossible to measure directly.

 

[RajD]

Maybe!

I’ve also noticed a steady efficiency increase. I have stats on my morning commute. On the exact same drive of 20.8 miles over the last month:

Configuration: GDE, 7-seat, 20/21 wheels, smooth, DDP on highway, odometer at 1812 miles, trip meter stats.

• Mon Jan 05: 3.39 mi/kWh
• Mon Jan 12: 3.38 mi/kWh, 41F
• Tue Jan 20: 3.59 mi/kWh, 49F
• Tue Jan 27: 3.53 mi/kWh, 44F
• Fri Jan 30: 3.88 mi/kWh, 49F (no idea why this is so good)

Note: this is the better leg of my commute with consistent traffic conditions.. The return leg is worse but traffic conditions vary quite a bit. Avg round trip is around ~3 mi/kWh.

Two other factors that I can think of for the improved efficiency (in addition to mechanical systems breaking in).

1. Charge loss (battery degradation) through formation/growth of SEI. This is why Lucid is saying you’ll get better range after 2k miles, although 2k isn’t a magic number. This charge loss is rapid for a new battery then slows down over time.
2. Temperatures have been gradually increasing. Nights are not as cold, so battery starts out warmer (although I park in my garage).

I have a month’s worth of data that I’ll crunch through when I get a chance. I’m curious as to how charge loss through SEI shows up in the data. @Cyp The Eastern Edge - NotchEV edition race may have provided a data point (maybe Tom would be interested since he has the numbers in his StateOfCharge video). At the end of the race, available charge went from 8% to 0% when the Gravity finally got to sit and rest. I wonder if that is the BMS adjusting for 2k miles of SEI (at least, as one factor). I imagine it’s impossible to measure directly.

How fast are you going on those commutes?

 

[Saksak]

How fast are you going on those commutes?

As fast as I can . I’m an aggressive but safe driver, IMHO. I don’t make unsafe maneuvers.

I try to hit 10 over the speed limit and no more. The first 5 miles are city with little traffic and I go 60 mph between lights (speed limit of 50). On the highway, it’s anywhere from 55 to 75 mph depending on traffic and the section of highway. I’m guessing I hit 75 for half the time on the highway (~8 miles) and 55-65 for the remaining half because of traffic.

I’ve purposely been easy on the throttle, though, treating the drives as if I had my family on board for a road trip. Not exactly gentle, but not ripping it, either, for the sake of data collection. Of course, my family says I drive like a crazy (but safe!) taxi driver…

 

[Saksak]

My round trip commute today with the crazy high efficiency (3.60 mi/kWh). EPA is 3.58 mi/kWh (420 mi / 117.39 kWh) for my configuration.

To work (sorry, I incorrectly transcribed 3.88 instead of 3.86 in my previous message):

To home (charged at work):

Let see if the numbers hold up in the coming week.

 

[mattrub]

Maybe!

I’ve also noticed a steady efficiency increase. I have stats on my morning commute. On the exact same drive of 20.8 miles over the last month:

Configuration: GDE, 7-seat, 20/21 wheels, smooth, DDP on highway, odometer at 1812 miles, trip meter stats.

• Mon Jan 05: 3.39 mi/kWh
• Mon Jan 12: 3.38 mi/kWh, 41F
• Tue Jan 20: 3.59 mi/kWh, 49F
• Tue Jan 27: 3.53 mi/kWh, 44F
• Fri Jan 30: 3.88 mi/kWh, 49F (no idea why this is so good)

Note: this is the better leg of my commute with consistent traffic conditions.. The return leg is worse but traffic conditions vary quite a bit. Avg round trip is around ~3 mi/kWh.

Two other factors that I can think of for the improved efficiency (in addition to mechanical systems breaking in).

1. Charge loss (battery degradation) through formation/growth of SEI. This is why Lucid is saying you’ll get better range after 2k miles, although 2k isn’t a magic number. This charge loss is rapid for a new battery then slows down over time.
2. Temperatures have been gradually increasing. Nights are not as cold, so battery starts out warmer (although I park in my garage).

I have a month’s worth of data that I’ll crunch through when I get a chance. I’m curious as to how charge loss through SEI shows up in the data. @Cyp The Eastern Edge - NotchEV edition race may have provided a data point (maybe Tom would be interested since he has the numbers in his StateOfCharge video). At the end of the race, available charge went from 8% to 0% when the Gravity finally got to sit and rest. I wonder if that is the BMS adjusting for 2k miles of SEI (at least, as one factor). I imagine it’s impossible to measure directly.

I wonder if there is anything special about this car I'm in Austin, Texas, normally warm weather and however I tried, I couldn't go beyond 3-3.05 mi/kwh. Mine is GT 7 seater 20/21 wheels.

 

[illopp00]

My guess is that mechanical systems are also wearing in. Somewhat equivalent to the initial break in period for engines.

Yes, at least with my Air it was quite easy to feel how tight the motor diffs were, you put it in roll and see how easy it is to roll down the driveway. In the cold its much slower, same for the early mileage.