Battery Electric Vehicle News / Enjoying the Transportation Revolution

Martyn1981

Great news, and certainly not before time - seems that early production Tesla Semi's are close to rolling out, and the rumour mill is suggesting they will have the 4680 batteries ..... probably safer waiting till the Q4 earnings report and see what Tesla say.

[Small aside, but seeing lots of the new electric buses driving around Cardiff, now just need the big noisy diesel refuse trucks to modernise. The future is nigh.]

First 15 Tesla Semi units to be delivered to PepsiCo by end of January: report

Sightings of what appeared to be freshly built Tesla Semis were reported near Gigafactory Nevada in late 2021, though by the end of the year, it seemed that PepsiCo would have to wait a bit longer before it could take delivery of its first electric trucks. This wait might not be very long, however, as recent reports from the electric vehicle community have suggested that PepsiCo may end up taking delivery of its first 15 Tesla Semis as early as this month. 

Martyn1981

With temps dropping, The Washington Post recently ran an article knocking EV's, to which Cleantechnica have responded, note, you can just skip to the third link.

Responding To The Washington Post Hatchet Job On Electric Cars & Winter Driving

But following the breadcrumbs through that article, and another by Inside Hook:

Can Electric Cars Survive in Winter?

Leads us to a recent comparison of warm weather v's freezing range across 13 BEV's, and suggests things aren't awful.

Why Does Winter Weather Affect Electric Vehicle Range?

JKenH

Martyn1981 said:

With temps dropping, The Washington Post recently ran an article knocking EV's, to which Cleantechnica have responded, note, you can just skip to the third link.

Responding To The Washington Post Hatchet Job On Electric Cars & Winter Driving

But following the breadcrumbs through that article, and another by Inside Hook:

Can Electric Cars Survive in Winter?

Leads us to a recent comparison of warm weather v's freezing range across 13 BEV's, and suggests things aren't awful.

Why Does Winter Weather Affect Electric Vehicle Range?

Well done CleanTechnica for calling out this blatantly biased anti EV journalism. 

What a jumped up jackass you are, sir! If you are wondering how such an ignorant stooge gets to publish his poisonous ideas, consider this from his Washington Post bio: “He is a … frequent panelist on Fox News’s Special Report and Fox News Sunday.” Oh, Fox News. Sure, now there’s a bastion of journalistic excellence for you. Did you notice how Lane took a deliberate swipe at Tesla? Shameful.

Good to see some unbiased comment to set the record straight.

I love the last link. The Model Y has better range when it’s cold outside! I suspect that’s just until you actually drive it somewhere. 

I actually got 3.7 miles per kWh from my Leaf on a a 100 mile plus motorway trip at the weekend after a rapid charge bumped up the battery temperature to 45*C.

JKenH

JKenH said:

Are Electric cars less efficient in winter?

I often see (and myself make) the comment that the fuel consumption of electric cars is greater in winter but is that actually the case? If I avoid using the heating will I see the same mpk (miles/kWh) in winter as summer? Yes the range will drop in my Leaf as it doesn’t  have a battery heater but the number of miles I get from each kWh shouldn’t yet it seems to. 

What I have noticed in most journeys (summer or winter) is that as my journey progresses the mpk displayed improves. Often at the end of the first mile it is around 2 mpk but then it creeps up. Does the transmission fluid warming up have that much impact? (I know from time spent with race cars on dynos that you have to not only get the engine warm but also the gearbox and diff oil to get the best performance but does cold transmission oil drag the efficiency down by as much as a third? 

My car lives in a well insulated attached garage usually with a door open adjacent to the boiler room so even in cold weather the temperature rarely drops into single figures.

When cold, tyres should have less rolling resistance (assuming the same pressures have been set the same cold) so that should improve efficiency and the cold air/ roads should stop them getting hot and sapping power as they might in hot weather.

The battery warms up as the car is driven which should deliver more energy but that shouldn’t have any effect on mpk.

Any thoughts from the engineers out there?

Finally, I have an answer to this question, courtesy of my son. His explanation:

All batteries have internal resistance, which is why they get hotter the more power you put through them (in or out). The internal resistance increases as the battery gets colder. Therefore, for a given level of driving power a cold battery will absorb more energy overcoming its internal resistance, which will make the kWh/ mile worse for the cold battery. This will also heat up the battery as you drive, so the efficiency will then improve.

michaels

JKenH said:

JKenH said:

Are Electric cars less efficient in winter?

I often see (and myself make) the comment that the fuel consumption of electric cars is greater in winter but is that actually the case? If I avoid using the heating will I see the same mpk (miles/kWh) in winter as summer? Yes the range will drop in my Leaf as it doesn’t  have a battery heater but the number of miles I get from each kWh shouldn’t yet it seems to. 

What I have noticed in most journeys (summer or winter) is that as my journey progresses the mpk displayed improves. Often at the end of the first mile it is around 2 mpk but then it creeps up. Does the transmission fluid warming up have that much impact? (I know from time spent with race cars on dynos that you have to not only get the engine warm but also the gearbox and diff oil to get the best performance but does cold transmission oil drag the efficiency down by as much as a third? 

My car lives in a well insulated attached garage usually with a door open adjacent to the boiler room so even in cold weather the temperature rarely drops into single figures.

When cold, tyres should have less rolling resistance (assuming the same pressures have been set the same cold) so that should improve efficiency and the cold air/ roads should stop them getting hot and sapping power as they might in hot weather.

The battery warms up as the car is driven which should deliver more energy but that shouldn’t have any effect on mpk.

Any thoughts from the engineers out there?

Finally, I have an answer to this question, courtesy of my son. His explanation:

All batteries have internal resistance, which is why they get hotter the more power you put through them (in or out). The internal resistance increases as the battery gets colder. Therefore, for a given level of driving power a cold battery will absorb more energy overcoming its internal resistance, which will make the kWh/ mile worse for the cold battery. This will also heat up the battery as you drive, so the efficiency will then improve.

This makes a lot of sense, we used to keep the leaf (no active battery temperature management) in the garage in winter and didn't seem to suffer any real reduction in range whereas now due to a surplus of junk it lives outside and cold mornings seem to see much lower efficiency for the first few miles.

thevilla

michaels said:

JKenH said:

JKenH said:

Are Electric cars less efficient in winter?

I often see (and myself make) the comment that the fuel consumption of electric cars is greater in winter but is that actually the case? If I avoid using the heating will I see the same mpk (miles/kWh) in winter as summer? Yes the range will drop in my Leaf as it doesn’t  have a battery heater but the number of miles I get from each kWh shouldn’t yet it seems to. 

What I have noticed in most journeys (summer or winter) is that as my journey progresses the mpk displayed improves. Often at the end of the first mile it is around 2 mpk but then it creeps up. Does the transmission fluid warming up have that much impact? (I know from time spent with race cars on dynos that you have to not only get the engine warm but also the gearbox and diff oil to get the best performance but does cold transmission oil drag the efficiency down by as much as a third? 

My car lives in a well insulated attached garage usually with a door open adjacent to the boiler room so even in cold weather the temperature rarely drops into single figures.

When cold, tyres should have less rolling resistance (assuming the same pressures have been set the same cold) so that should improve efficiency and the cold air/ roads should stop them getting hot and sapping power as they might in hot weather.

The battery warms up as the car is driven which should deliver more energy but that shouldn’t have any effect on mpk.

Any thoughts from the engineers out there?

Finally, I have an answer to this question, courtesy of my son. His explanation:

All batteries have internal resistance, which is why they get hotter the more power you put through them (in or out). The internal resistance increases as the battery gets colder. Therefore, for a given level of driving power a cold battery will absorb more energy overcoming its internal resistance, which will make the kWh/ mile worse for the cold battery. This will also heat up the battery as you drive, so the efficiency will then improve.

This makes a lot of sense, we used to keep the leaf (no active battery temperature management) in the garage in winter and didn't seem to suffer any real reduction in range whereas now due to a surplus of junk it lives outside and cold mornings seem to see much lower efficiency for the first few miles.

When I was at school a long time ago, lower temperature was associated with lower electrical resistance.  I think the fact lithium batteries are dependent upon a chemical reaction which will be slower as the temperature drops is a more likely pointer.

I understand the Leaf and other EVs use resistive cabin heating initially before relying upon a more efficient heat pump. I think this partly explains a big drop in efficiency for the first 10 minutes driving and means preconditioning while on charge should mitigate much of it. I have been taken back once or twice in our Leaf at the phenomenon 🙂

ABrass

thevilla said:

michaels said:

JKenH said:

JKenH said:

Are Electric cars less efficient in winter?

I often see (and myself make) the comment that the fuel consumption of electric cars is greater in winter but is that actually the case? If I avoid using the heating will I see the same mpk (miles/kWh) in winter as summer? Yes the range will drop in my Leaf as it doesn’t  have a battery heater but the number of miles I get from each kWh shouldn’t yet it seems to. 

What I have noticed in most journeys (summer or winter) is that as my journey progresses the mpk displayed improves. Often at the end of the first mile it is around 2 mpk but then it creeps up. Does the transmission fluid warming up have that much impact? (I know from time spent with race cars on dynos that you have to not only get the engine warm but also the gearbox and diff oil to get the best performance but does cold transmission oil drag the efficiency down by as much as a third? 

My car lives in a well insulated attached garage usually with a door open adjacent to the boiler room so even in cold weather the temperature rarely drops into single figures.

When cold, tyres should have less rolling resistance (assuming the same pressures have been set the same cold) so that should improve efficiency and the cold air/ roads should stop them getting hot and sapping power as they might in hot weather.

The battery warms up as the car is driven which should deliver more energy but that shouldn’t have any effect on mpk.

Any thoughts from the engineers out there?

Finally, I have an answer to this question, courtesy of my son. His explanation:

All batteries have internal resistance, which is why they get hotter the more power you put through them (in or out). The internal resistance increases as the battery gets colder. Therefore, for a given level of driving power a cold battery will absorb more energy overcoming its internal resistance, which will make the kWh/ mile worse for the cold battery. This will also heat up the battery as you drive, so the efficiency will then improve.

This makes a lot of sense, we used to keep the leaf (no active battery temperature management) in the garage in winter and didn't seem to suffer any real reduction in range whereas now due to a surplus of junk it lives outside and cold mornings seem to see much lower efficiency for the first few miles.

When I was at school a long time ago, lower temperature was associated with lower electrical resistance.  I think the fact lithium batteries are dependent upon a chemical reaction which will be slower as the temperature drops is a more likely pointer.

I understand the Leaf and other EVs use resistive cabin heating initially before relying upon a more efficient heat pump. I think this partly explains a big drop in efficiency for the first 10 minutes driving and means preconditioning while on charge should mitigate much of it. I have been taken back once or twice in our Leaf at the phenomenon 🙂

In normal conductors lower temperature does reduce resistance, but a battery is very different. The chemical process you mention is what determines the internal resistance.

JKenH

Tesla's New LFP Battery Truly Shines in Sub-Zero Temperatures, Looks Like a Winner

For those who keep count, regular Li-Ion batteries start to lose their efficiency in the cold, and not even LFPs have a good record in this regard.

But, alas, a Tesla Model 3 RWD featuring the new battery showed impressive results in the range test.

https://www.autoevolution.com/news/tesla-s-new-lfp-battery-truly-shines-in-sub-zero-temperatures-looks-like-a-winner-178846.html

Martyn1981

Another report/result that basically boosts BEV buses.

French City Cancels Hydrogen Bus Contract, Opts For Electric Buses

The public transit agency for the city of Montpellier, on the southern coast of France between Toulouse and Marseilles, has cancelled a contract to procure 51 new buses powered by hydrogen fuel cells, citing concerns about their cost of operation. Few things are more important to a fleet manager than the cost per kilometer for fuel, which is computed down to the thousandth of a euro. When vehicles are traveling millions of kilometers a year, every centime counts.

Now, La Tribune says new city president Michaël Delafosse has decided to discontinue the project as the financial calculations underlying the proposed joint venture have not turned out as expected. Specifically, the city calculates it would cost them 95 cents per kilometer for the hydrogen fueled buses versus 15 cents per kilometer for battery-powered buses. In addition, the cost of the fuel cell-powered buses was between €150,000 and €200,000 more than the cost of battery-powered buses.

Grumpy_chap

Martyn1981 said:

Another report/result that basically boosts BEV buses.

I can see in many cases, EV would work well for buses. 

The bus is often parked up overnight in the same location so making provision for charging is simple.
The bus takes pretty much the same route / load every day, so knowing the required charging capacity is calculatable and repeatable.
Buses spend a large amount of time idling, which is the worst possible thing for ICE.

Buses that operate 24-hour routes are less easy as the transport operator won't see obvious sense in needing twice as many buses so that the day and night routes can be served.

I suppose bus stations would also need to have diesel generators as back-up power to get the fleet charged overnight in the event of grid power supply failure.  It would be very costly if the whole city had to take a day off work just because of a power black-out meaning the buses were not charged sufficiently to meet the next day's work.