Bad Efficiency Getting Worse?

[Nano]

Here is a great video that shows the affect of temperature on EV range done by Consumer Reports. Best range was 85degree day even with AC and even the 65 degree day was worse and the 17 degree day obviously worse still.

I was surprised as they were even the 65 degree day affected range for all EV’s tested. The video is maybe 60 secs.

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[zefram47]

I've noticed the same for me, the battery was generally on the low end around 59 and slowly warmed during the commute. Now I get in and it's 72, it clearly heated itself up before I got near it. Range dropped about 5%, welcome to winter. Let me know when you do a subzero road trip, then we'll talk efficiency drops

That doesn't explain my 72°F battery when charging ended 7 hours prior and garage temp is 50°F.

Pretty sure this is incorrect. This past weekend we got down into the teens with my truck garaged. Battery got down to 50F, but never seems to have warmed itself up except through charging and driving. Now a week later my battery is finally back up into the 70s, but it just increased a couple degrees per day through driving and charging alone. My overall efficiency this week has been almost normal at around 2.2-2.3 mi/kWh. The motor temps on my truck were around 100F all week until last night when I finally saw them back around the 130-140F mark once the battery reached 70F. That said, except for days below freezing I don't run the cabin heat. At most I put the fan on the lowest speed with no temperature control and just use the seat and steering wheel heaters.

If I had to guess, it's the OP running cabin heat. From the thread about the motor temps showing unexpectedly high, it looks like the R1 doesn't actively warm the battery unless it's below 50F. As for the battery staying warm...there's a ton of thermal mass sitting there and it takes awhile for it to naturally warm or cool just sitting doing nothing, regardless of the outside temperature. As above, charging definitely warms it and the more energy you put into the pack during your charge the more it will warm up.

 

[Riviot]

Pretty sure this is incorrect. This past weekend we got down into the teens with my truck garaged. Battery got down to 50F, but never seems to have warmed itself up except through charging and driving. Now a week later my battery is finally back up into the 70s, but it just increased a couple degrees per day through driving and charging alone. My overall efficiency this week has been almost normal at around 2.2-2.3 mi/kWh. The motor temps on my truck were around 100F all week until last night when I finally saw them back around the 130-140F mark once the battery reached 70F. That said, except for days below freezing I don't run the cabin heat. At most I put the fan on the lowest speed with no temperature control and just use the seat and steering wheel heaters.

If I had to guess, it's the OP running cabin heat. From the thread about the motor temps showing unexpectedly high, it looks like the R1 doesn't actively warm the battery unless it's below 50F. As for the battery staying warm...there's a ton of thermal mass sitting there and it takes awhile for it to naturally warm or cool just sitting doing nothing, regardless of the outside temperature. As above, charging definitely warms it and the more energy you put into the pack during your charge the more it will warm up.

Which part is incorrect, my battery warming or how my battery warmed? It definitely warmed, how is up for debate. I'll credit charging, sure. But it didn't spontaneously warm.

Multiple times I've left the truck with the HVAC off having not used floor vents, and got back in to the floor vents running hot (when cold outside) or cold (when hot outside). Please explain that ?

IRT heated seats and wheel only vs using cabin heat, I'm in the heated cabin camp now. I didn't buy a $90k truck to wear gloves and a coat in it, I'm going to be comfortable in my commute even if it means not electrons used.

 

[zefram47]

Which part is incorrect, my battery warming or how my battery warmed? It definitely warmed, how is up for debate. I'll credit charging, sure. But it didn't spontaneously warm.

Multiple times I've left the truck with the HVAC off having not used floor vents, and got back in to the floor vents running hot (when cold outside) or cold (when hot outside). Please explain that ?

IRT heated seats and wheel only vs using cabin heat, I'm in the heated cabin camp now. I didn't buy a $90k truck to wear gloves and a coat in it, I'm going to be comfortable in my commute even if it means not electrons used.

Referring to how the battery is getting warmer and why it doesn't markedly cool off overnight.

Oh the truck definitely vents to the cabin while charging for some reason. Even mid-summer I'd notice the cabin getting warm while charging and I have no idea why. As soon as charging starts you can hear a fan come on, but it's not clear why that would be linked to the cabin at all.

 

[Riviot]

Referring to how the battery is getting warmer and why it doesn't markedly cool off overnight.

Oh the truck definitely vents to the cabin while charging for some reason. Even mid-summer I'd notice the cabin getting warm while charging and I have no idea why. As soon as charging starts you can hear a fan come on, but it's not clear why that would be linked to the cabin at all.

My uneducated speculative guess is the wall above the pack is the thinnest one and allows HVAC/cabin condition (that humans generally like to keep the same temp the batteries like) to double as a thermal assistant for batteries.

 

[Rivian Head]

Not impressed with my efficiency… and it seems to be getting worse.

21” R1T

Yes, the temperature has dropped recently. Today was 55. We had our first freeze last night.

For the last 400+ miles, I’ve not been able to break above 2.0mi/kWH. It’s like the mid line is a brick wall for my truck now.

I have all these new meters and can’t correlate any reason for it. Battery, mostly has been 75 +/- 10. Motor temps not interesting.

Anyone else?

My Trip B meter is at 2.11mi/kWH over 13k miles. Total log 14.5k miles.

So strange. I am getting 2.3-2.5 even in 30-50 deg weather.

 

[vista1984]

So strange. I am getting 2.3-2.5 even in 30-50 deg weather.

temp is one thing, there are many other factors:
speed, altitude, load, tire, road condition.

but if there are any doubts, should submit a service ticket, local tech should have some ideas.

 

[vista1984]

My uneducated speculative guess is the wall above the pack is the thinnest one and allows HVAC/cabin condition (that humans generally like to keep the same temp the batteries like) to double as a thermal assistant for batteries.

i think they must have mentioned here. I am too lazy to watch. It is not heat pump so not really motivate to watch.

 

[Rivifan]

Watching this thread as ive only been in my R1T for four months now, so first winter here, and have noticed my guessometer in the drivers cluster will drop up to 20% beyond actual miles driven lately... I was just about to start documenting this for more detail thinking this is abnormal.

I plan to track: ambient temp & battery temp at start (which will indicate garage or outside kept, as we share a spot) and end, cabin temp or off, how leadfoot i drove (low/med/high), and now reading this post, tire pressure too.
Hoping to graph some correlations on most impactful to range loss.
Should i track anything else?

Or is this normal expected behavior that the guessometer drops faster than the odometer in <ideal conditions?

 

[goldburger]

Check your tire PSI and make sure you are inflating back back to factory specs. Cold weather causes tire pressure to drop an you are likely hurting your efficiency.

Cold is obviously going to impact as well.

My loaner truck one 20's has 44 psi tires and is getting far better efficiency than OP's truck, which is mostly short trips.

 

[SASSquatch]

My loaner truck one 20's has 44 psi tires and is getting far better efficiency than OP's truck, which is mostly short trips.

44 psi isn't that far off the OEM recommendation or am I missing something?

Shorter trips should definitely result in better efficiency because of the high amount of regen.

 

[emoore]

44 psi isn't that far off the OEM recommendation or am I missing something?

Shorter trips should definitely result in better efficiency because of the high amount of regen.

Shorter trips are most definitely not better efficiency.

 

[vista1984]

Watching this thread as ive only been in my R1T for four months now, so first winter here, and have noticed my guessometer in the drivers cluster will drop up to 20% beyond actual miles driven lately... I was just about to start documenting this for more detail thinking this is abnormal.

I plan to track: ambient temp & battery temp at start (which will indicate garage or outside kept, as we share a spot) and end, cabin temp or off, how leadfoot i drove (low/med/high), and now reading this post, tire pressure too.
Hoping to graph some correlations on most impactful to range loss.
Should i track anything else?

Or is this normal expected behavior that the guessometer drops faster than the odometer in <ideal conditions?

maybe altitude gain/loss and wind speed..

and.. i think gauge is good enough for recording efficiency but i also notice that it does not go above 4. just to say it has its limitation.

 

[Craigins]

Should i track anything else?

Wind speed and direction. Road conditions (dry, wet, snow). Weather (rain, snow, sunny, cloudy)

 

[cruiser]

Have seen the same in R1S. down from mid 2s to high 1s. Guess it's likely running the heater on short trips.

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