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Back in January I started keeping track of the temperature and kWh used for my 19.1 mile commute to work. I excluded those days my son missed the bus and I had to drop him off at school and those days with adverse weather conditions. I always drive the same route, always go without climate control. So any difference can be almost 100% attributed to the affect of air temperature on range.

One plot on the graph (2F) was actually from about 2 years ago. I found and old post here and I had the temperature and kWh used, so I was able to add it. It matched up almost perfectly. I wish I started collecting this data earlier. Oh well, live and learn.

 

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Thank you for this information!

Not to toot my horn (mostly because I stole this rule of thumb from someone else), but it seems that your Volt is losing very close to 5-6% efficiency for every 10 F the temperature drops. Hmm. Maybe EVs don't suffer more range loss during winter than ICEVs.
 

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My wife has had as little as 13 miles of range on a single charge. But unlike Ari, she uses climate control!

Still sounds bad, but the reality is the vehicle is likely performing normally.

Why? Well, she has a one-way commute of 1.5 miles, works for 8 hours, and commutes back. Along with 30F temperatures, that basically means every mile travelled with the climate control drawing maximum power. Add in a remote start each time here and there, and it only gets worse.

On the bright side, she stays warm and gas usage is still avoided except on real cold ERDTT days. ;)
 

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Discussion Starter #4
Thank you for this information!

Not to toot my horn (mostly because I stole this rule of thumb from someone else), but it seems that your Volt is losing very close to 5-6% efficiency for every 10 F the temperature drops. Hmm. Maybe EVs don't suffer more range loss during winter than ICEVs.
This is only because I drive without heat. My wife's 2016 Volt now has almost the same range as my 2012 Volt. Of course she stays toasty warm, and my Volt resembles a popsicle. But, I get to collect data!
 

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This is only because I drive without heat. My wife's 2016 Volt now has almost the same range as my 2012 Volt. Of course she stays toasty warm, and my Volt resembles a popsicle. But, I get to collect data!
True, but the Volt has a very small battery (or defaults to ICE during cold), so this gives a very good baseline to extrapolate from. This could mean that you could drive your same route in the Bolt only using 5-6 kWh for propelling the vehicle and another 3-4 kWh for climate control.
 

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Discussion Starter #6
True, but the Volt has a very small battery (or defaults to ICE during cold), so this gives a very good baseline to extrapolate from. This could mean that you could drive your same route in the Bolt only using 5-6 kWh for propelling the vehicle and another 3-4 kWh for climate control.
Not mine, I have the ERDTT hack, so the only time I use my ice is for fuel and engine maintenance. Last time my ICE was used for another reason was May 2012.
 

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Thank you for this information!

Not to toot my horn (mostly because I stole this rule of thumb from someone else), but it seems that your Volt is losing very close to 5-6% efficiency for every 10 F the temperature drops. Hmm. Maybe EVs don't suffer more range loss during winter than ICEVs.
Try not plugging in an EV and see what happens to your range in winter (charge it then unplug it). Let the battery get nice and cold. :)

Most of us plug our cars in overnight, so some energy is used from the wall to keep the battery warm. A "block" heater so to speak.

Gasoline cars have lower efficiency until they warm up the block, but given 70% or so waste heat, they can do so quickly without much loss. As a side bonus they can pump a large portion of that waste heat back into the cab and keep the occupants warm.

Thanks for the data set ari, nice to see cold effects.
 

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As an owner of two Gen I's and was one of the knuckleheads that drove in a COLD car (unless the wife was with me) I now find as on owner of a Gen II that bigger battery and possibly more efficient HVAC system (and heated steering wheel) allows me to set the HVAC to AUTO, ECO and 74 degrees and even in temps as low as 4 degrees here in St Louis I'm now comfortable and don't fight fogged up windows. The range hit was right at 15-17 miles. Pre cold temps my GOM hovered at 63-67 miles and now it reads 46-48 miles.

Amazing how 4 more kW of power change everything.
 

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Ari, is this a plot of the cars behavior after burping the battery and getting it warm or plugged in but hours after the charge finished?

For me (going by range not energy off the wall) I can keep my "full" range down to about 18 degrees if I get the battery warm prior to departure, but below that the battery heater seems to use more juice than I can regain on L1.
 

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Discussion Starter #11 (Edited)
Ari, is this a plot of the cars behavior after burping the battery and getting it warm or plugged in but hours after the charge finished?

For me (going by range not energy off the wall) I can keep my "full" range down to about 18 degrees if I get the battery warm prior to departure, but below that the battery heater seems to use more juice than I can regain on L1.
This is using my technique of turning on the Volt hours after a charge completed and letting it continue to charge until the charging amps drops to 5.0. This maximizes the additional charge and can result in an extra 3% bump in the SOC winter time, less so during warmer weather. However, I did this on all days, even when it was relatively warm. There is still a boost in the SOC when it is 80F, just not as much.
 

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...Amazing how 4 more kW of power change everything.
It is interesting to look at the 'Daily Driving' plots for the various by-year groups on voltstats. One tends to read about how 'the average driver drives xx miles a day, so that is all the battery one needs'. But comparing the various Gen 1 DD plots to the Gen 2 plots, it is clear that Gen 2 has passed a significant threshold.

For example, here is the 2013 group (click on Daily Driving): http://www.voltstats.net/Stats/GroupDetails/105

And here is the 2016 group: http://www.voltstats.net/Stats/GroupDetails/248

Note in the 2013 group the fairly rapid falloff in EV-only usage after about 40 miles. I interpret this to say a lot of Gen 1 owners hit the battery limit, then run in hybrid mode the rest of the day. However in the 2016 plot, the EV-only peak is clear, and the falloff is far more gradual after the peak. This seems to say that Gen 2 really does handle the majority of most folks average daily driving chores, with some to spare (e.g., for cold weather, etc.)

In our case, if we had a Gen 1, we would definitely be burning a little bit of gas on many days - especially in the colder weather. Gen 2 is handling things, though some days it is really close. Another 3-4 kWh of usable battery would really do it for me.
 

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Back in January I started keeping track of the temperature and kWh used for my 19.1 mile commute to work.
Kudos for this experiment ari_c! This is great evidence.

The takeaway from your graph is that the Volt loses about 25% range between summer-like 70-ies and freezing (32F). That is precisely my experience as well. Yesterday we had a rare near-freezing day here in Silicon Valley, and my range dropped to 32 miles. My summer range is ~42 miles for the same commute and drive pattern.
 

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It is interesting to look at the 'Daily Driving' plots for the various by-year groups on voltstats. One tends to read about how 'the average driver drives xx miles a day, so that is all the battery one needs'. But comparing the various Gen 1 DD plots to the Gen 2 plots, it is clear that Gen 2 has passed a significant threshold.

For example, here is the 2013 group (click on Daily Driving): http://www.voltstats.net/Stats/GroupDetails/105

And here is the 2016 group: http://www.voltstats.net/Stats/GroupDetails/248

Note in the 2013 group the fairly rapid falloff in EV-only usage after about 40 miles. I interpret this to say a lot of Gen 1 owners hit the battery limit, then run in hybrid mode the rest of the day. However in the 2016 plot, the EV-only peak is clear, and the falloff is far more gradual after the peak. This seems to say that Gen 2 really does handle the majority of most folks average daily driving chores, with some to spare (e.g., for cold weather, etc.)

In our case, if we had a Gen 1, we would definitely be burning a little bit of gas on many days - especially in the colder weather. Gen 2 is handling things, though some days it is really close. Another 3-4 kWh of usable battery would really do it for me.
Interesting, my 2017 (Von Zipper) is sitting at 99.7% and both of my Gen I's (Patty Wagen and Bazinga) ended at 92.6% nothing else has really changed in my daily driving. I'm a creature of habit.
 

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ari_c: quick question: I get an effective range between 32miles (cold winter day) and 43 (summer) in my 2013 Volt. With about 10kWh net available per charge, that is 4.2miles/kWh tops. How do you get 5.5miles/kWh in summer? Even if I tried to hypermile, I never got even close to that.
 

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Discussion Starter #16
ari_c: quick question: I get an effective range between 32miles (cold winter day) and 43 (summer) in my 2013 Volt. With about 10kWh net available per charge, that is 4.2miles/kWh tops. How do you get 5.5miles/kWh in summer? Even if I tried to hypermile, I never got even close to that.
All depends on how fast you drive. On my commute I avoid highways as much as possible. Speed kills range. That's why I was able to get almost 82 miles on one charge in my 2012 Volt.

How fast do you drive on your commute if you try and hypermile?
 

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A couple of weeks ago I managed to get 5.3 MPKWh on a 29 mile trip to Needham MA. The temps were in the 30s so I didn't need heat or AC and I preconditioned the car before leaving but the most important thing was speed. Half of the trip was on a back road at 35 MPH but the second half was on Route 128 which was running at horse an buggy speeds, 10MPH all the way.
 

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My wife has had as little as 13 miles of range on a single charge. But unlike Ari, she uses climate control!

Still sounds bad, but the reality is the vehicle is likely performing normally.

Why? Well, she has a one-way commute of 1.5 miles, works for 8 hours, and commutes back. Along with 30F temperatures, that basically means every mile travelled with the climate control drawing maximum power. Add in a remote start each time here and there, and it only gets worse.

On the bright side, she stays warm and gas usage is still avoided except on real cold ERDTT days. ;)
I've been cranking the heat lately in my '12. This morning, I saw 25 miles on the GOM after a full charge. I only have a 17 mile RT commute though, so I can crank away. :D
 

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Shouldn't the graph flatten out at the top and actually start to go down >100 degrees?
In practice it would. His data does not include heating and cooling because he drives without using any temperature control in the cabin.
 
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