Bad Efficiency Getting Worse?

[Golfer04]

If you keep the cabin warm (mine is on auto at 71) winter range stinks. I've never had it improve substantially on a 100 mile trip either. Some say it does, but never for me. Mine is garaged and plugged in all night. Easily lose 20 percent off the range. I'm not convinced it is all cabin temp either. Why doesn't my summer range go down after sitting outside in the sun all day? Fan and a/c comes on big time.

Sponsored

 

[Riviot]

Outside. Before the temp gauges, I would assumed “cold soak”. But the battery has mainly been right up the middle most of those 400.

The battery is in the middle because your truck is using up electrons to keep it warm. Plus all your short trips it's conditioning a lot and immediately being shut off when most conditioning is done. Rinse, repeat.

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

 

[R1Tom]

The battery is in the middle because your truck is using up electrons to keep it warm. Plus all your short trips it's conditioning a lot and immediately being shut off when most conditioning is done. Rinse, repeat.

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

I am trying to figure out how it is heating the batteries? I thought it was with the run the motors hot trick, but is there some other way? I thought someone said there is no heater for the battery system?

 

[Riviot]

I am trying to figure out how it is heating the batteries? I thought it was with the run the motors hot trick, but is there some other way? I thought someone said there is no heater for the battery system?

I think it uses the cabin resistive heaters, I'll get in and the floor vents will be pumping hot air with the cab all warmed up. The same way it'll blow cold air when trying to cool it during fast charge.

 

[SASSquatch]

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.

 

[R1Tom]

I think it uses the cabin resistive heaters, I'll get in and the floor vents will be pumping hot air with the cab all warmed up. The same way it'll blow cold air when trying to cool it during fast charge.

I would love a complete schematic on the display that shows all devices, valves, fluid cooler, etc... with all temps, valve positions, etc... I am sure we won't get that level, and I certainly love what we got with this last update...but that next level of data would be fun to know.

 

[Throwdown]

I am trying to figure out how it is heating the batteries? I thought it was with the run the motors hot trick, but is there some other way? I thought someone said there is no heater for the battery system?

Charging heats the battery, electrons flowing causes heat, even extremely slow charging on a 110v outlet will increase the battery temp.

 

[Riviot]

Charging heats the battery, electrons flowing causes heat, even extremely slow charging on a 110v outlet will increase the battery temp.

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

 

[Craigins]

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

Sure it does. The battery is insulated and gets very hot when charging. Mine is typically over 90 degrees when charging off the 120. My cabin also gets nice and warm while charging.

With no air flow to dissipate the heat it will take quite awhile for the pack to cool to ambient.

In another thread there were non believers who refuse to acknowledge that charging heats the battery and the only way to heat the battery is with resistive heating.

 

[Smeek]

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.

you seem to really be discounting the effect of cold weather. you can expect a ~25% reduction in range in cold weather. unfortunately this is not an exaggeration.

is this your first fall/winter with an EV?

 

[elektrode]

is this your first fall/winter with an EV?

No, but it’s everyone’s first fall winter without having to hunt for trip meters and having temperature instrumentation for their Rivian.

I doubt current owners fully understand how to correlate all this new data. I think I don’t. Point taken.

 

[R.I.P.]

We are back down to two Teslas. One of them has a heat pump, one does not. Every time fall/winter comes around I am surprised all over again at the difference between the two. The Tesla w/o the heat pump takes a huge range hit in the cold.

Resistive heating takes a ton of power; peaking out at 6kw when it gets cold. A HP can produce similar heat using 1.5kw.

 

[Smeek]

No, but it’s everyone’s first fall winter without having to hunt for trip meters and having temperature instrumentation for their Rivian.

I doubt current owners fully understand how to correlate all this new data. I think I don’t. Point taken.

good point.

my last EV was an audi which gave you efficiency per trip and kept that data for the life of the car. it was very easy to see your efficiency progressively drop as it got a bit colder out and then plummet in the dead of winter. it’s a good way to manage expectations of the customers, i think.

 

[dgennetten]

On a different note, I enjoyed experiencing this all the way down from Chambers Lake (West of Fort Collins). I wish it didn't peg at 4.01, though I understand the math/dataViz justification.

What I didn't expect was much higher efficiency during the half-hour of in-town travels after coming down from the mountains. I cannot make sense of it.

 

[SDH]

We are back down to two Teslas. One of them has a heat pump, one does not. Every time fall/winter comes around I am surprised all over again at the difference between the two. The Tesla w/o the heat pump takes a huge range hit in the cold.

Resistive heating takes a ton of power; peaking out at 6kw when it gets cold. A HP can produce similar heat using 1.5kw.

what he says.

Sponsored