Eletric cars are they worth it - do you have one

lordmountararat

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

uknick

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

Pretty much nothing, once the cabin has got to the desired temperature.

Back in the summer of 2018 I was using my i3 to commute to central London.  This was a 2 hour journey of about 30 miles.  5 miles was in London congested traffic.  During that time we had some really hot days, about the same as now.  When I left work about 4pm for the first week I left the a/c off to save battery and cooled the car the old fashion way, opening the windows.  For the next week I used the a/c and found no noticeable change in battery usage.

Using the heater in the winter is the battery killer.    

ComicGeek

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

My Skoda Enyaq uses around 1 kW per hour in very hot weather to run the radio and AC, I use it a lot to work between meetings. That's equivalent to around 3 miles of range, for every hour of AC usage. So 1% of range for every hour that the AC is on, not really significant! I drove last year in 40 degree heat and didn't notice any difference to range.

Some makes are less efficient, but it's really winter that's the issue.

born_again

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

My E-Niro drops range by 3 miles when getting into a hot car, but once car is at required temp. It makes no difference to range. One good downhill stretch can see that reclaimed no bother.
If owners are doing that then either they are right on the edge of their range, or the hardcore that never bother with HVAC. Personally, I'm using my EV just the same as my old ICE. 

As you say. In a ICE, you should not be in stopped traffic for any length of time with engine running. So if you abide the law, you too would be fanning & sweating. 

Not sure it's the situation is much more pressing and urgent in an electric car than ICE.

Reverse this in winter in heavy snow & trapped in car. I would rather be in a EV than a ICE as once snow builds up. You have to turn ICE off or you can kill yourself with the fumes. Not a issue in a EV.

Martyn1981

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

It is a good question, and worth asking. As others have said it's not much, I think a heatpump for A/C cn draw as much as 1kW, but only when at full power. And 1kW for a whole hour is only 1kWh, so for a battery of 50-80kWh it's not much, and as others point out, only high power to reach desired cabin temp, maybe 5mins?

For an ICE vehicle it will be far more energy*. Firstly you need to power the A/C vi power takeoff from the engine, which is inefficient, and unlikely to be using a heatpump (of course, not all BEV's have a heatpump). So engine running even in stationary traffic to keep the A/C on, will use a lot of petrol/diesel, and not pleasant breathing that in, in the car.

In the US and Australia, there have been quite a lot of brush fires started by police cars sitting on the side of the road, with the engine running (for the A/C) and the exhaust or catalytic converter have set fire to the dry grass and started a fire, sometimes destroying the car too.

*Edit - missed off the keyword. Thanks to born_again for clarifying any confusion I may have caused. M.

born_again

Martyn1981 said:

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

It is a good question, and worth asking. As others have said it's not much, I think a heatpump for A/C cn draw as much as 1kW, but only when at full power. And 1kW for a whole hour is only 1kWh, so for a battery of 50-80kWh it's not much, and as others point out, only high power to reach desired cabin temp, maybe 5mins?

For an ICE vehicle it will be far more. Firstly you need to power the A/C vi power takeoff from the engine, which is inefficient, and unlikely to be using a heatpump (of course, not all BEV's have a heatpump). So engine running even in stationary traffic to keep the A/C on, will use a lot of petrol/diesel, and not pleasant breathing that in, in the car.

In the US and Australia, there have been quite a lot of brush fires started by police cars sitting on the side of the road, with the engine running (for the A/C) and the exhaust or catalytic converter have set fire to the dry grass and started a fire, sometimes destroying the car too.

Many ICE the compressor is now electric powered, so does not require this take off. As efficient as they can be. 👍

Martyn1981

born_again said:

Martyn1981 said:

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

It is a good question, and worth asking. As others have said it's not much, I think a heatpump for A/C cn draw as much as 1kW, but only when at full power. And 1kW for a whole hour is only 1kWh, so for a battery of 50-80kWh it's not much, and as others point out, only high power to reach desired cabin temp, maybe 5mins?

For an ICE vehicle it will be far more. Firstly you need to power the A/C vi power takeoff from the engine, which is inefficient, and unlikely to be using a heatpump (of course, not all BEV's have a heatpump). So engine running even in stationary traffic to keep the A/C on, will use a lot of petrol/diesel, and not pleasant breathing that in, in the car.

In the US and Australia, there have been quite a lot of brush fires started by police cars sitting on the side of the road, with the engine running (for the A/C) and the exhaust or catalytic converter have set fire to the dry grass and started a fire, sometimes destroying the car too.

Many ICE the compressor is now electric powered, so does not require this take off. As efficient as they can be. 👍

Yep, I tried to cover my bets with a more vague term. But isn't the electricity produced from the alternator, which is a power take-off? With a petrol car running at about 25% efficiency in best conditions, before considering the leccy generation losses, then when idling, the leccy generation will be around 5-10% efficient?

born_again

Martyn1981 said:

born_again said:

Martyn1981 said:

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

It is a good question, and worth asking. As others have said it's not much, I think a heatpump for A/C cn draw as much as 1kW, but only when at full power. And 1kW for a whole hour is only 1kWh, so for a battery of 50-80kWh it's not much, and as others point out, only high power to reach desired cabin temp, maybe 5mins?

For an ICE vehicle it will be far more. Firstly you need to power the A/C vi power takeoff from the engine, which is inefficient, and unlikely to be using a heatpump (of course, not all BEV's have a heatpump). So engine running even in stationary traffic to keep the A/C on, will use a lot of petrol/diesel, and not pleasant breathing that in, in the car.

In the US and Australia, there have been quite a lot of brush fires started by police cars sitting on the side of the road, with the engine running (for the A/C) and the exhaust or catalytic converter have set fire to the dry grass and started a fire, sometimes destroying the car too.

Many ICE the compressor is now electric powered, so does not require this take off. As efficient as they can be. 👍

Yep, I tried to cover my bets with a more vague term. But isn't the electricity produced from the alternator, which is a power take-off? With a petrol car running at about 25% efficiency in best conditions, before considering the leccy generation losses, then when idling, the leccy generation will be around 5-10% efficient?

Yes, true. But it is not a separate take off.
Given a alternator will only charge battery at a max rate, the load will be no more than normal.

Martyn1981

born_again said:

Martyn1981 said:

born_again said:

Martyn1981 said:

lordmountararat said:

This is a serious question and I'm not trying to score points, but how much battery does air conditioning use up on a really hot day? I was stopped on the M5 on Wednesday, inching forward for over two hours because of an earlier fatality. The outside temperature was in excess of 27  degrees C. I noticed a couple of electric cars with windows open and occupants fanning themselves with newspaper. Presumably they had to switch off the air conditioning because of course they wouldn't know how long they would be delayed and how long the battery would last. I realise that ICE cars can run out of fuel too, but the situation is much more pressing and urgent in an electric car. This scenario alone would put me off buying one.

It is a good question, and worth asking. As others have said it's not much, I think a heatpump for A/C cn draw as much as 1kW, but only when at full power. And 1kW for a whole hour is only 1kWh, so for a battery of 50-80kWh it's not much, and as others point out, only high power to reach desired cabin temp, maybe 5mins?

For an ICE vehicle it will be far more. Firstly you need to power the A/C vi power takeoff from the engine, which is inefficient, and unlikely to be using a heatpump (of course, not all BEV's have a heatpump). So engine running even in stationary traffic to keep the A/C on, will use a lot of petrol/diesel, and not pleasant breathing that in, in the car.

In the US and Australia, there have been quite a lot of brush fires started by police cars sitting on the side of the road, with the engine running (for the A/C) and the exhaust or catalytic converter have set fire to the dry grass and started a fire, sometimes destroying the car too.

Many ICE the compressor is now electric powered, so does not require this take off. As efficient as they can be. 👍

Yep, I tried to cover my bets with a more vague term. But isn't the electricity produced from the alternator, which is a power take-off? With a petrol car running at about 25% efficiency in best conditions, before considering the leccy generation losses, then when idling, the leccy generation will be around 5-10% efficient?

Yes, true. But it is not a separate take off.
Given a alternator will only charge battery at a max rate, the load will be no more than normal.

Hi, not arguing, hope you are enjoying this digression too. But won't an idling car increase the rpms when AC is running, so it increases the fuel burn, to produce the leccy to power the AC, rather than use/drain the battery?

I was wondering if my estimate of efficiency was reasonable, so if a petrol car produces leccy at 10% efficiency, then over an hour (if consuming 1kW), it would need to burn 10kWh of petrol. A gallon (imp) of petrol has about 42kWh of energy in it, so that's around a quarter of a gallon per hour, which I thought sounded high, but after some Googling, the suggestion seems to be that idling uses about 1/5th to 1/3rd of a gallon (US gallon 33.7kWh)), but this increases 'significantly'(?) when AC is switched on, suggestions of 1/2gall (US) per hour, or ~16kWh of energy.

So perhaps a bit worse than I'd initially thought. Does that sound too high to you?

lordmountararat

Thanks for all the responses. That day every ICE car with air conditioning was using it, believe me, illegal or not (and surely not - that would be absurd!) We didn't choose to be held up for such a long time. Does anyone know why it is necessary to close a motorway for 12 hours following a fatality? There was no diesel spill to clear up.