The EV fact thread

[davymead]

Hopefully everyone on here with an EV or a LEV will watch this , we might also hope those who manage/own ferries/tunnels/ hotels/shopping centres/underground car parks/blocks of flats/office blocks etc also absorb it.

Intriguing and an eye opener for many I’d imagine. Thanks for posting.

 

[clk320x]

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Fascinating talk on lithium battery safety... Sleep well

How did you stumble upon this? 7.9k views in 3 months, clearly not a lot of interest in his talk. Do you go out of your way looking for EV fire related videos?

New EVs are using LiFePO4 batteries anyway which are far safer than the already extremely conventional batteries used in older cars.

 

[Noitz]

... LiFePO4 batteries anyway which are far safer than the already extremely conventional batteries used in older cars.

But then LiFePO4 batteries have lower energy density, higher cost, and limited availability compared to Lithium-ion batteries and can still go into thermal runaway.

 

[philnewmerc]

You could equally drive an ICE car with the aircon off to increase range, but the Aussies for example might not be too keen on this solution....

I've experimented with this in the past and never noticed any difference in MPG, the drain from a compressor must be minuscule compared with the load of moving two tons of metal

 

[philnewmerc]

How did you stumble upon this? 7.9k views in 3 months, clearly not a lot of interest in his talk. Do you go out of your way looking for EV fire related videos?

New EVs are using LiFePO4 batteries anyway which are far safer than the already extremely conventional batteries used in older cars.

Forgive me but you seem rather sensitive on the EV subject to the point of believing any discussion on the topic is automatically some kind of insult. If you have no worries then why on earth are you bothered about this video from a worldwide leading expert on lithium batteries? This is a buildings safety research conference presentation on the fire risk to buildings from lithium batteries, where experts share their research data and opinions... If you watch it you'll see most of the talk is not about EVs: please see my thumbnail for more information

My take home message was not don't buy an EV (although it does give food for thought especially leaving kids or pets in one) it was don't charge my electric bike inside when I'm not in

 

[philnewmerc]

Hopefully everyone on here with an EV or a LEV will watch this , we might also hope those who manage/own ferries/tunnels/ hotels/shopping centres/underground car parks/blocks of flats/office blocks etc also absorb it.

My first thought was I shouldn't be charging my electric bike when I'm not in... And because EV fires are still relatively speaking very rare I don't think it would put me off one as I suppose petrol cars catch fire spontaneously but with EVs it seems to be at any point whether they're hot or cold or have not been driven for hours or days... Unpredictable is unnerving imho. Would EV owners be happy to leave your kids or pets having watched the video?

 

[markjay]

I've experimented with this in the past and never noticed any difference in MPG, the drain from a compressor must be minuscule compared with the load of moving two tons of metal

In fact, I seem to remember reading somewhere that when driving on the motorway on a hit summer day, the fuel consumption with the AC on is actually lower than when driving with all the windows winded down (due to drag).

 

[markjay]

However.... this is the first result in Google search...:

But I guess that the extra load affects smaller engines disproportionately, so (say) a 1.6L 4-Cyl will be worse affected than a (say) 3.0L V6.

 

[philnewmerc]

In fact, I seem to remember reading somewhere that when driving on the motorway on a hit summer day, the fuel consumption with the AC on is actually lower than when driving with all the windows winded down (due to drag).

I think that is correct. I also reckon that running the compressor regularly is a good way of avoiding it seizing up or the seals going bad through not using it believing it to save money... Catching the pennies and missing the pounds etc.

Anyway, in order to keep this EV relevant I am contractually obliged to say that EV drivers who avoid using aircon to save range may end up costing them more in the long run (apologies if this is incorrect, I have no idea if the aircon works in the same way...).

On the other hand not using the heater is not a problem as far as I know, so in the winter, EV drivers who make their wives sit in the cold to save range will have no financial detriment in the future, apart from the divorce* .

*Joke!

 

[MikeInWimbledon]

However.... this is the first result in Google search...:

But I guess that the extra load affects smaller engines disproportionately, so (say) a 1.6L 4-Cyl will be worse affected than a (say) 3.0L V6.

I wish !!

When the Russkies invaded Ukraine and fuel prices jumped, I floated the question on here as to whether we should switch off the Air Con on our vehicles.

The consensus on here was “Don’t be daft, it’s a saving of barely one or two percent, Guv. We’ll keep our air con on, even if it’s £1.90 a litre.”

If anyone knows how I can save up to 20% of my fuel consumption by switching off the air con, I’d love to know how.

 

[markjay]

I wish !!

When the Russkies invaded Ukraine and fuel prices jumped, I floated the question on here as to whether we should switch off the Air Con on our vehicles.

The consensus on here was “Don’t be daft, it’s a saving of barely one or two percent, Guv. We’ll keep our air con on, even if it’s £1.90 a litre.”

If anyone knows how I can save up to 20% of my fuel consumption by switching off the air con, I’d love to know how.

Surely you're not suggesting that Mr Google got it wrong......?

 

[markjay]

I think that the issue here is that the 20% figure is not incorrect as such, but it is probably an extreme example, e.g. for a car with a small engine and an old-fashioned mechanical compressor (the AC on modern small cars is usually electric, making it much more energy efficient).

Ultimately, it's probably a biased claim like those often made regarding EVs: it takes a particular and extreme set of circumstances and tries to present it as the norm.

 

[ALFAitalia]

20% lol! I've never noticed any measurable difference AC on or off in any modern car. A modern compressor steels about 3 hp to spin. So a pretty tiny percentage of a modern cars output....and of course its not compressing all the time if its not hot weather as the clutch will release it when it gets down to your preset temp.
Older cars could use up to 8 hp! I remember when they first started to offer AC on the 1.4 engine Mk 3 Golf.....it was only 60 hp to start with....if you cranked up the AC when the car was on idle the engine would almost stall until the idle stabiliser caught up!! Im sure a little underpowered engine like that might notice a worse % mpg drop that a modern car....but not 20%.

 

[grober]

Lithium-ion battery fire safety - Best Magazine

The professors profile

 

[philnewmerc]

However.... this is the first result in Google search...:

But I guess that the extra load affects smaller engines disproportionately, so (say) a 1.6L 4-Cyl will be worse affected than a (say) 3.0L V6.

I suppose that's possible, but I've had small cars and never noticed a difference. I just had a quick Google and only pages that say 10 or 20% never have a research source, it just seems to be like a urban myth. I'm not saying it doesn't increase fuel consumption, it must do, but I reckon it will be almost undetectable unless one is a hypemiler.

I wish !!

When the Russkies invaded Ukraine and fuel prices jumped, I floated the question on here as to whether we should switch off the Air Con on our vehicles.

The consensus on here was “Don’t be daft, it’s a saving of barely one or two percent, Guv. We’ll keep our air con on, even if it’s £1.90 a litre.”

If anyone knows how I can save up to 20% of my fuel consumption by switching off the air con, I’d love to know how.

If your car has six horsepower, and you are using a air conditioning compressor that draws one horsepower, leaving you with five horsepower, then switching it off will increase your horsepower from five to six, which is a 20% increase in power, and hence, in my mind at least, efficiency...

 

[ALFAitalia]

LOL....true.....but most cars produce a bit more than 6 hp.......unless you drive one of these.....and if you do I'm fairly sure AC was not an option in 1905!

 

[SmartAmg]

20% lol! I've never noticed any measurable difference AC on or off in any modern car. A modern compressor steels about 3 hp to spin. So a pretty tiny percentage of a modern cars output....and of course its not compressing all the time if its not hot weather as the clutch will release it when it gets down to your preset temp.
Older cars could use up to 8 hp! I remember when they first started to offer AC on the 1.4 engine Mk 3 Golf.....it was only 60 hp to start with....if you cranked up the AC when the car was on idle the engine would almost stall until the idle stabiliser caught up!! Im sure a little underpowered engine like that might notice a worse % mpg drop that a modern car....but not 20%.

Agreed.

 

[Bellow]

However.... this is the first result in Google search...:

But I guess that the extra load affects smaller engines disproportionately, so (say) a 1.6L 4-Cyl will be worse affected than a (say) 3.0L V6.

In all probability, that 20% figure will be when the vehicle is stationary, engine idling.
Bear in mind the minimum and maximum fuel flow rates in a typical petrol engine vary by a factor of circa 100. Picking off the lowest to compare the AC draw to is pretty lame.
Alternatively, I am wrong and a 200hp engined car's AC compressor consumes 40hp.

 

[MikeInWimbledon]

I suppose that's possible, but I've had small cars and never noticed a difference. I just had a quick Google and only pages that say 10 or 20% never have a research source, it just seems to be like a urban myth. I'm not saying it doesn't increase fuel consumption, it must do, but I reckon it will be almost undetectable unless one is a hypemiler.

If your car has six horsepower, and you are using a air conditioning compressor that draws one horsepower, leaving you with five horsepower, then switching it off will increase your horsepower from five to six, which is a 20% increase in power, and hence, in my mind at least, efficiency...

So mine’s 385 bhp.
Talk me through the numbers

 

[MikeInWimbledon]

BTW. Being an old geezer, I prefer to drive without Air Con, unless I either feel the need for it, or remember that I haven’t run it for an age, typically because it’s been parked up.

But I’m very much in the minority. My guess is that it’s only a 1% difference