Tesla switching SR models to LFP batteries

[wayner]

This could have ramifications for Canadians, assuming that they use this battery technology for Canadian models due to being more affected by cold weather:

“LFP has both positive and negative trade-offs,” said Sam Abuelsamid, Guidehouse Insights principal analyst. “It’s significantly cheaper and doesn’t require any nickel or cobalt. It’s also more stable, which makes it safer.”

One major downside: The cells are less energy-dense, which means they offer lower range for the same weight as other cells. Cold weather also affects them more, Abuelsamid said.

Tesla will change the type of battery cells it uses in all its standard-range cars

The move is likely a way for Tesla to increase profit margins on its vehicles, while not necessarily having to raise vehicle prices.

www.cnbc.com

 

[angus[Y]oung]

This could have ramifications for Canadians, assuming that they use this battery technology for Canadian models due to being more affected by cold weather

@wayner I'm guessing Tesla has decided the trade-offs are worth it, since they are now adopting LFP globally for standard range vehicles. Canada is not the only cold climate they sell into (think: Norway and such), so they must have decided that it's tenable for their colder-weathered customers.

 

[wayner]

Agreed. I wonder what the exact tradeoffs are? If you only get a SR vehicle and it loses more range in the winter then that could make it less viable for some parts of Canada that are (a) colder, and (b) don't have a dense SC network. That is less of an issue for folks here in Southern Ontario that are on the 400 series of highways.

 

[theothertom]

I wonder what the exact tradeoffs are

As previously mentioned, LFP cold weather range will suffer. Pre-heating the battery will help but may not always be possible.
Look at the graph at time 20:04. (-10C)

 

[wayner]

This seems to be the relevant chart. Without preheating the range would be way down. I would have thought that heating the batteries would take more energy than is implied in this graph.

 

[Darthbenji]

Can you heat the pack when the car is unplugged?

 

[Big Earl]

Can you heat the pack when the car is unplugged?

Yes but it requires considerable energy to do so. 3+ kWh to bring it to 20°C from 0°C. It can be worth it but one must plan accordingly.

 

[Darthbenji]

Ordered a new one two weeks ago and no longer have access to home charging. If it’s LFP I’m concerned my winter range will be even worse than the current battery.

 

[PovertySpec3]

Agreed. I wonder what the exact tradeoffs are? If you only get a SR vehicle and it loses more range in the winter then that could make it less viable for some parts of Canada that are (a) colder, and (b) don't have a dense SC network. That is less of an issue for folks here in Southern Ontario that are on the 400 series of highways.

I think the benefit of being able to charge to 100% all the time is pretty big. Most Tesla owners in Canada will be charging at home and can heat the car prior to departure anyway; those that live and charge in condos will usually be parked in parkades, which are usually a hell of a lot warmer than outside.

I'm on the west coast, so NMC in my '21 is fine. People rarely bring up the weight savings of NMC - they're almost 300lbs lighter. That's huge - like having 2 passengers in your car - that has a major effect on range and performance.

 

[theothertom]

I would have thought that heating the batteries would take more energy than is implied in this graph.

I must've missed it. How much energy is used (or implied) to heat the battery?

 

[theothertom]

Most Tesla owners in Canada will be charging at home and can heat the car prior to departure anyway;

Yes, but can they heat the car at work? I guess they could but they wouldn't be plugged in so that they would have to consume battery % to do that?

 

[wayner]

I must've missed it. How much energy is used (or implied) to heat the battery?

It isn't spelled out explicitly, but presumably it would be the difference between the red bars at -20c vs higher temperatures, say 10C in the chart in post #5 of this thread. Eyeballing it from the charts that only seems to be a loss of about 20km in range. There are probably a whole bunch of assumptions behind this, such as how often the car has to be reheated from the ambient temperature.

 

[theothertom]

It isn't spelled out explicitly, but presumably it would be the difference between the red bars at -20c vs higher temperatures, say 10C in the chart in post #5 of this thread. Eyeballing it from the charts that only seems to be a loss of about 20km in range. There are probably a whole bunch of assumptions behind this, such as how often the car has to be reheated from the ambient temperature.

To me, the important thing about the chart is the difference between the blue bars(cold LFP battery) and the gray (cold NMC battery). Looks like there's ~30% loss in range over what you would "normally" get with a "standard" battery.

 

[USBSeawolf2000]

The chart shows NMC but Tesla use NCA. They may have similar low temp performance but something to note.

Heating LFP is definitely worth it if it takes 3kWh as mentioned above. It takes ~12 miles worth of energy to gain ~100 miles of usable range. I assume the range loss in the chart is temporary loss (snow icon) that gains back after warming up.

 

[theothertom]

The chart shows NMC but Tesla use NCA. They may have similar low temp performance but something to note.

Heating LFP is definitely worth it if it takes 3kWh as mentioned above. It takes ~12 miles worth of energy to gain ~100 miles of usable range. I assume the range loss in the chart is temporary loss (snow icon) that gains back after warming up.

Bottom line is the jury is still out so what I've said is somewhat speculation, as are my comments below. I'm not trying to be argumentative, I'm just trying to look ahead and say "what if".

I missed the 3kWh above? Still couldn't find the reference. Based on my Chevy Bolt it's about twice that. My guess is it'd take about 10% of the battery to heat itself up, so you'd loose 10% range due to heating.
I agree that range would improve after heating but again that consumes battery power if not plugged in.
It's going to be interesting when the real world data comes in. I really hope range doesn't drop that much and I'd be surprised if Tesla doesn't have a trick or two up their sleeves to keep the range hit from being too large.

 

[wayner]

To me, the important thing about the chart is the difference between the blue bars(cold LFP battery) and the gray (cold NMC battery). Looks like there's ~30% loss in range over what you would "normally" get with a "standard" battery.

Agreed, but the video says that this is negated by heating the battery up. And that loss is way more than 30% at -20C

 

[USBSeawolf2000]

Bottom line is the jury is still out so what I've said is somewhat speculation, as are my comments below. I'm not trying to be argumentative, I'm just trying to look ahead and say "what if".

I missed the 3kWh above? Still couldn't find the reference. Based on my Chevy Bolt it's about twice that. My guess is it'd take about 10% of the battery to heat itself up, so you'd loose 10% range due to heating.
I agree that range would improve after heating but again that consumes battery power if not plugged in.
It's going to be interesting when the real world data comes in. I really hope range doesn't drop that much and I'd be surprised if Tesla doesn't have a trick or two up their sleeves to keep the range hit from being too large.

Post #7 mentioned 3+kWh.

I don't think Bolt has heat pump. Model 3 LFP does (except early units in Europe) but the advantage/difference would be less at -20C.

I have preheated my LFP in 50F outdoor for 13 mins plugged into Wall Connector. Battery temp went from 50F to 60F when the cabin temp reached 72F. Per my Sense Energy Monitor, it initially drew ~4.5kW for 3 mins and ramps down to ~4kW. It used less than 1kWh, just a reference point for the upcoming winter.

 

[theothertom]

Post #7 mentioned 3+kWh.

I don't think Bolt has heat pump. Model 3 LFP does (except early units in Europe) but the advantage/difference would be less at -20C.

I have preheated my LFP in 50F outdoor for 13 mins plugged into Wall Connector. Battery temp went from 50F to 60F when the cabin temp reached 72F. Per my Sense Energy Monitor, it initially drew ~4.5kW for 3 mins and ramps down to ~4kW. It used less than 1kWh, just a reference point for the upcoming winter.

Thanks! Good info. Keep us informed on how the range does in winter.

Edit: Correct, the Bolt does not have a heat pump.

 

[theothertom]

Agreed, but the video says that this is negated by heating the battery up. And that loss is way more than 30% at -20C

Yeah, that's the key. What I don't know (maybe someone does?) is how long to heat, how much energy is consumed, etc. But a warm battery should negate the range loss.
Edit: Maybe Tesla will make battery heating automatic if the car is plugged in. Or maybe give us the option to make it automatic even if it's not plugged in. I wish they would do that with NCA as well.

 

[Big Earl]

Yeah, that's the key. What I don't know (maybe someone does?) is how long to heat, how much energy is consumed, etc. But a warm battery should negate the range loss.
Edit: Maybe Tesla will make battery heating automatic if the car is plugged in. Or maybe give us the option to make it automatic even if it's not plugged in. I wish they would do that with NCA as well.

The only time NCA really needs heating is before charging. Otherwise it’s a waste of energy with little benefit. The only time I’ve found it to be worthwhile is prior to departure on a road trip, getting the battery up to temp with shore power rather than battery power in preparation for Supercharging. For around-town use, preheating is a waste.

The amount of energy required to heat the battery depends on how cold the battery is. Keep in mind that the 1,000 lb pack will heat very slowly. As @USBSeawolf2000 described above, a 10°F rise took 15 minutes and about 1 kWh. To go from 0°F to 50°F will take considerably more time and energy.

I think it’s also important to highlight this part of Tesla’s webpage. I’ll be very interested to see how people like their LFP packs this winter in Canada - seems they’ve been selling very well up there.