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Discussion Starter · #1 ·
Getting used to the new car - so far so good. Just wondering about preconditioning the battery before driving. Is there an ambient temperature where preconditioning doesn't really help much with efficiency? My garage temp even in the winter rarely goes below 11C or 52F. I preconditioned for about 30 mins with the ambient around 17C or 62F today before leaving. Using a juicebox40A.

According to the journey log my efficiency improved to 21.1kWh/100km compared to 23.8 kWh/100km for the same trip a few days ago. I also did switch from comfort to ECO mode.

So just wondering if there are days where I just shouldn't bother preconditioning - in the summer when temps are 24c-27c, or 75-80F?.

G
 

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Getting used to the new car - so far so good. Just wondering about preconditioning the battery before driving. Is there an ambient temperature where preconditioning doesn't really help much with efficiency? My garage temp even in the winter rarely goes below 11C or 52F. I preconditioned for about 30 mins with the ambient around 17C or 62F today before leaving. Using a juicebox40A.

According to the journey log my efficiency improved to 21.1kWh/100km compared to 23.8 kWh/100km for the same trip a few days ago. I also did switch from comfort to ECO mode.

So just wondering if there are days where I just shouldn't bother preconditioning - in the summer when temps are 24c-27c, or 75-80F?.

G
Hi G,

Just searching the forums looking for comments about the effect of preconditioning on consumption/range. Have you (or others) got much of a sense of how much preconditioning the car/battery helps?
 

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It makes a significant difference, this preconditioning. At 5°C, climate preconditioning will draw around 2kWh in 20mins to heat up the cabin. Those same kWh you would spend from the battery while driving in the first 20mins anyway, so for me that is a no-brainer.

For Battery preconditioning, about 12% difference, or 3kWh/100km/almost 5kWh/100mi.
I did the same run twice, with and without battery preconditioning. Climate preconditioning in both cases, ECO mode for both.
At 5°C over 90km of highway I achieved 25kWh/100km (aka 40kWh/100mi or 2.5mi/kWh) when looking only at the high speed stretch (130kmh, 81mph). Without battery preconditioning, consumption was 28kWh/100km.
Overall, so including lower speed stretches and traffic jams and detours, with preconditioning I achieved 22.5kWh/100 vs 25.5 without.
 

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It makes a significant difference, this preconditioning. At 5°C, climate preconditioning will draw around 2kWh in 20mins to heat up the cabin. Those same kWh you would spend from the battery while driving in the first 20mins anyway, so for me that is a no-brainer.

For Battery preconditioning, about 12% difference, or 3kWh/100km/almost 5kWh/100mi.
I did the same run twice, with and without battery preconditioning. Climate preconditioning in both cases, ECO mode for both.
At 5°C over 90km of highway I achieved 25kWh/100km (aka 40kWh/100mi or 2.5mi/kWh) when looking only at the high speed stretch (130kmh, 81mph). Without battery preconditioning, consumption was 28kWh/100km.
Overall, so including lower speed stretches and traffic jams and detours, with preconditioning I achieved 22.5kWh/100 vs 25.5 without.
Thanks G
I noticed similar results. Did a little 80-90km trip last week with no preconditioning - some city traffic and about 60km of 100km/hr highway driving up and down some hills. No preconditioning was bang on 25kwh/100km. With preconditioning for the same trip this past weekend (similar temps) I saw 22.6 kWh/100km.

For day to day trips to work or around town, not much point apart from warming the car up for my cold hands. But for a longer journey where reaching a DCFC station might be important, the extra range or improved consumption achieved by plugging in, charging to 100%SOC and preconditioning likely helps.
 

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Discussion Starter · #5 ·
I don't precondition for my 30 minute commute. For long trips to the cottage it helps to maximize the range. Nice to have a warm car in the morning if you're parked outside or garage is very cold.
 

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Forgive me if I'm stating something obvious here but I thought I'd take the opportunity to point out a couple of factoids to the folks that are reading this thread because JLR's explanation of preconditioning is confusing.

There's cabin preconditioning, which you can use to warm up (or cool down) the kitty's interior whether or not the vehicle is plugged in.
Then there's battery preconditioning, which only happens if you have the vehicle plugged in and you do cabin preconditioning.

It's my understanding that when the battery is cold because you're in Minnesota in January or god forbid Saskatchewan (in January too) or even New Hampshire in February or Northern Sweden at any time ... When the battery is cold, battery preconditioning will warm it up so that it's at a better operating temperature during your drive, which saves energy overall. And of course you'll have used the grid and not your battery to warm up the cabin to nice and warm in your brutal Siberian conditions, which helps too.

By the same token, if you're in Phoenix or Needles or Death Valley in July or Alice Springs in January, preconditioning will cool the battery when you're plugged into a fast charger, which would otherwise bring the battery temperature to undesirable levels even higher than the ambient temperature. 🍺
 

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....For Battery preconditioning, about 12% difference, or 3kWh/100km/almost 5kWh/100mi.
I did the same run twice, with and without battery preconditioning. Climate preconditioning in both cases, ECO mode for both.
At 5°C over 90km of highway I achieved 25kWh/100km (aka 40kWh/100mi or 2.5mi/kWh) when looking only at the high speed stretch (130kmh, 81mph). Without battery preconditioning, consumption was 28kWh/100km.
Overall, so including lower speed stretches and traffic jams and detours, with preconditioning I achieved 22.5kWh/100 vs 25.5 without.
Nice data but be careful about the conclusions.

What you are quoting is energy usage over 90km, massaged to x kWh/100km. This should not be used to compute the energy usage for the next 90km since at this point the battery should be at approximately the same temperature in both scenarios.
I agree that this indicates an ~ 3kWh cost for bringing the battery up to temperature, but this is a one off cost. If we assume a range of 240miles on a full charge (not likely in mid winter) this 3kWh cost would equate to less than 10miles of lost range over a long journey.
Preconditioning the battery (and cabin) prior to a winter journey does no harm, but doesn't provide tremendous advantages.
 

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The trip from my home to the ski hill is 250km, the last 18km being from sea level straight up to 1200m.

If I fully charge my car and then precondition, the extra 10km of range might make all the difference!! I can pretty much make it up on a full charge without too much concern, but the extra buffer would be reassuring.

Of course, coming home I coast straight down the hill and add a bunch of range (if I'm not fully charged before we leave the hill).
 

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.....If I fully charge my car and then precondition, the extra 10km of range might make all the difference!! I can pretty much make it up on a full charge without too much concern, but the extra buffer would be reassuring....
That's the point. You can "pretty much make it up on a full charge without too much concern". If you couldn't make w/o preconditioning would the extra the extra 8-10 miles of possible range encourage you to try? From my experience the range on a full charge is too dependent on external variables that I would not be that bold. Think "head wind" or "drop in temperature" or "small detour due to accident" etc.
 

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That's the point. You can "pretty much make it up on a full charge without too much concern". If you couldn't make w/o preconditioning would the extra the extra 8-10 miles of possible range encourage you to try? From my experience the range on a full charge is too dependent on external variables that I would not be that bold. Think "head wind" or "drop in temperature" or "small detour due to accident" etc.
You are bang on correct Q!!!

My winter range at sea level at 5C is about 320km, so getting up to the ski hill 250km away should be a no-brainer, right? There are DCFC stations along the way, so no problem to stop, if necessary. BUT..... without stopping to charge I'm always worried with that last 18km going straight up the mountain. Will try the preconditioning move next time we go skiing (in 2 weeks, I think) and can report back regarding how much it helps.

As you all suggest, I may notice a minor improvement in range/consumption - but if I'm getting anxious on the road, I will still pull over for a little more juice.
 

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Discussion Starter · #12 ·
All the ski 'hills' in Ontario are closed due to Covid unfortunately. Are there chargers at your hill for patrons/members to use?
 
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