Cold weather range and battery temperature

[jimk]

Departed at 8AM today headed from my home to Stratton Ski Resort, which is 33.5 miles away (all on 2-lane state highways), with a net elevation gain of approx 1400 feet. Car was charged to 95% but not plugged in when I departed and the outside temp was 16F. At departure, my battery temp was 27F and motors were all 32F.
...
At 8:48, on arrival at Stratton, outside temp was 21F, battery was 59F and motor temps had dropped to 129-140F. The car reported 72% range remaining, so I used approximately a quarter of my car's range to drive 33 miles.

Repeated the drive this morning. Outside temps were in the low 30s and I left the truck on the charger overnight. Range at departure was 98% (probably because I switched on climate 15 minutes before I departed). Range at arrival was 79%. Battery was in the mid-50s when I departed and stayed around there the whole time. Motor temps never went above the 150s.

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[usulio]

The 16% usage from ABRP already has the elevation gain taken into account.
So the rest of 7% is for battery preconditioning and cabin heating, well also assuming tire pressure etc are at nominal conditions.

That's fine, but ABRP is just making guesses, I am trying to stick to facts. (And did you mean 17%?)

 

[usulio]

Repeated the drive this morning. Outside temps were in the low 30s and I left the truck on the charger overnight. Range at departure was 98% (probably because I switched on climate 15 minutes before I departed). Range at arrival was 79%. Battery was in the mid-50s when I departed and stayed around there the whole time. Motor temps never went above the 150s.

Ok, nice, 19% total battery usage instead of 33%, thanks to preheating. But also exterior temps ~16 degrees warmer this time. Good info.

 

[iansriv]

68 mph will get you 310 easy if you don't have wind....in my experience. Conserve and low setting and 6 coats of wax.

Most normal humans have wind. And collectovely Texas has a lot of wind. Wax on!

 

[DaveA]

Most normal humans have wind. And collectovely Texas has a lot of wind. Wax on!

 

[DTown3011]

Repeated the drive this morning. Outside temps were in the low 30s and I left the truck on the charger overnight. Range at departure was 98% (probably because I switched on climate 15 minutes before I departed). Range at arrival was 79%. Battery was in the mid-50s when I departed and stayed around there the whole time. Motor temps never went above the 150s.

In my experience, cold weather below 15* absolutely crushes the battery so doing anything you can (preconditioning, etc) is very helpful. Looking forward to the new update that will allow this to be on schedule!

 

[RexRemus]

Below 20F all EV really suffer... Even Tesla with the heat pump.

Until the update here is what I recommend:

Drop charge limit to 10% below your normal charge limit. Set a reminder on your phone, go into the app 1 hour before your departure and increase charge limit at least 10%. This will charge the battery and heat it up some.

Alternatively, if you know how long it will take to charge you can set a charging schedule so that it starts charging and stops right when your ready to depart. If you want to do this, use the EV charging time calculator here:

https://www.inchcalculator.com/electric-vehicle-charging-time-calculator/

If your charging at the full 48 amps it's 11kw. This will get you pretty darn close ?

I've been doing exactly this and it works reasonably well. Though I've been setting up a schedule a bit further out and then dropping the max amperage to make it take about an hour or so - that seems to get a bit more heat in (despite the lower push of energy into the pack) vs doing it shorter/faster - as I find that you really need to nail the departure window. Having it go a bit slower/longer (intentionally make sure it's STILL charging that last bit as I'm about to leave) seems to work best. I can leave with a 50/60F degree battery most times and it only heats up to about 67 when driving so it's pretty close to "running temp" from the start

 

[AlcesBull]

I have some anecdata here. A trip last week from Denver to Basalt (outside of Aspen, CO). This trip is 180 miles with about 12k total elevation gain.

I left my house with 93% SoC after being plugged into my 120v overnight (which trickle charges ~1.5kw/h), and I arrived with 12% SoC after no stops. It was a little hairy in the first 50 mi because range guesstimate dropped a bunch going up to the Eisenhower Tunnel, for reasons I assume were similar to what you saw. I didn't pay extremely close attention to the battery data but I did clock significant motor temps in my first 50 miles. Guesstimate leveled out on the descent. I never went faster than ~75 mph so I definitely drive slower than a lot of I70 folks.

Reading your account makes me wonder if your trip was longer if things might balance out a little? On trips just up loveland pass (~45-50 mi from home, all uphill ~5k') I seem to smoke about 30% SoC if I leave cold though, again, this is an impression because I haven't been that worried about it yet.

 

[bc81620]

I have some anecdata here. A trip last week from Denver to Basalt (outside of Aspen, CO). This trip is 180 miles with about 12k total elevation gain.

I left my house with 93% SoC after being plugged into my 120v overnight (which trickle charges ~1.5kw/h), and I arrived with 12% SoC after no stops. It was a little hairy in the first 50 mi because range guesstimate dropped a bunch going up to the Eisenhower Tunnel, for reasons I assume were similar to what you saw. I didn't pay extremely close attention to the battery data but I did clock significant motor temps in my first 50 miles. Guesstimate leveled out on the descent. I never went faster than ~75 mph so I definitely drive slower than a lot of I70 folks.

Reading your account makes me wonder if your trip was longer if things might balance out a little? On trips just up loveland pass (~45-50 mi from home, all uphill ~5k') I seem to smoke about 30% SoC if I leave cold though, again, this is an impression because I haven't been that worried about it yet.

Do you have a dual or quad motor? Which size battery pack? Which wheels and tires are you running? Thanks!

 

[Epicloop]

Couldn’t make it home in “conserve” at 73 mph, w slight headwind Last 60 miles.

What was your motor & battery temps? I read in another thread that below a certain temp running conserve was not effective since the motor/s? where not producing enough heat to keep the battery at optimal operating temperature. I have not tested this yet.
https://www.rivianforums.com/forum/...date-conserve-only-helps-in-warm-temps.21751/

 

[Epicloop]

Does this sound within reasonable expectations to you folks?

What is you configuration? QM/DM, Large/Max, 20"/21"22"
The numbers seem reasonable for hilly winter travel without knowing the above or average speed.
33 miles/23% = 144 miles uphill in the cod no preconditioning
66 miles/31% = 213 miles return no preconditioning
66 miles/27% = 244 miles return trip with preconditioning

 

[RAD1]

Now that the new update is out, I would keep my vehicle plugged in and precondition the battery. I also spend the weekends in VT. This is what I do.

 

[jimk]

What is you configuration? QM/DM, Large/Max, 20"/21"22"
The numbers seem reasonable for hilly winter travel without knowing the above or average speed.
33 miles/23% = 144 miles uphill in the cod no preconditioning
66 miles/31% = 213 miles return no preconditioning
66 miles/27% = 244 miles return trip with preconditioning

Quad motor, large, 21"

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