Cold weather affecting predicted range

[Barrie1956]

In cold weather, I can quite understand that putting the heater on will cost me a chunk of my EV range. That's only to be expected. I'll see the range drop by about 6 miles. However, what I can't get my head around is that turning on the heater also causes the ICE to run. Again, I can kind of see the logic of this, using the waste heat from the engine. But the EV range stays at its "compromised" level, even though the ICE is providing the heat AND driving the car!! What am I missing?

 

[PHEV07]

What Year is your vehicle and what temperatures are you driving in?

 

[littlescrote]

The heater is usually not the cause of reduced range in cold weather. At maximum output it's only a kW or 2 which is insignificant compared to driving at any speed. The biggest cause of reduced range in cold weather as the reduced efficiency of the chemical reaction in the batteries, not to do with extra power consumption from ancillaries. Commonly misunderstood and just adds to the oil industry FUD keeping people out of EVs. Opponents will often say "the heater will drain the battery in a traffic jam" when it really doesn't. A 1kW heater will sustain a very high interior temperature in all weathers and with a modest 50kWh battery would take 50 hours to drain the battery. It's just nonsense.

 

[Lon12]

The heater is usually not the cause of reduced range in cold weather. At maximum output it's only a kW or 2 which is insignificant compared to driving at any speed. The biggest cause of reduced range in cold weather as the reduced efficiency of the chemical reaction in the batteries, not to do with extra power consumption from ancillaries. Commonly misunderstood and just adds to the oil industry FUD keeping people out of EVs. Opponents will often say "the heater will drain the battery in a traffic jam" when it really doesn't. A 1kW heater will sustain a very high interior temperature in all weathers and with a modest 50kWh battery would take 50 hours to drain the battery. It's just nonsense.

Where do you see a one or two kW heater? Typical is six or seven kW for an electric heater. Three kW is not bad for the heat pump. Sure if it isn't cold out the heat pump may get down to two. But if it is sunny out you probably will not be using it anyway at the warmer temperatures.

 

[RossWilliams]

Your typical little space heater uses 1500 watts but it isn't going to provide the kind of heat you get from your car heater. I think we tend to underestimate how much power is required to create heat and overestimate how much it takes to get a car to move. On a flat surface a single person can usually get a car rolling and keep it rolling. I learned to drive on my mother's Sunbeam Imp that wouldn't go into reverse. You could open the driver's door, put a foot out and push it back. It wasn't the size of an Outlander, but it doesn't really take that much energy to move a car compared to heating a space.

 

[BobK]

In cold weather, I can quite understand that putting the heater on will cost me a chunk of my EV range. That's only to be expected. I'll see the range drop by about 6 miles. However, what I can't get my head around is that turning on the heater also causes the ICE to run. Again, I can kind of see the logic of this, using the waste heat from the engine. But the EV range stays at its "compromised" level, even though the ICE is providing the heat AND driving the car!! What am I missing?

Often the air conditioning comes on to dehumidify the air while heating. Since the heat pump is needed to air condition, the ICE is needed to heat. Also, if it is too cold for the heat pump to heat, the ICE will come on (or the dash will warn you about the loss of heat if it is in EV mode). The range guessometer is very primitive and doesn't take much into account.

 

[Mike Aus]

In cold weather, I can quite understand that putting the heater on will cost me a chunk of my EV range. That's only to be expected. I'll see the range drop by about 6 miles. However, what I can't get my head around is that turning on the heater also causes the ICE to run. Again, I can kind of see the logic of this, using the waste heat from the engine. But the EV range stays at its "compromised" level, even though the ICE is providing the heat AND driving the car!! What am I missing?

 

[AndyInOz]

When you driving along, with the heating or air-conditioning off, the car is using x power.

When you turn on the heating, the car is now using x + y power.
(y is the amount of extra power being requested.)

Depending on the value of y, the battery may not be able to provide that amount of power on its own. (The value of y appears to be related to the difference between the current temperature and the target temperature.)

If the battery cannot provide x + y on its own, the engine starts to run the generator.

(If the engine is already running, under these circumstances, the revs increase to meet the new demand for power.)

 

[Barrie1956]

When you driving along, with the heating or air-conditioning off, the car is using x power.

When you turn on the heating, the car is now using x + y power.
(y is the amount of extra power being requested.)

Depending on the value of y, the battery may not be able to provide that amount of power on its own. (The value of y appears to be related to the difference between the current temperature and the target temperature.)

If the battery cannot provide x + y on its own, the engine starts to run the generator.

(If the engine is already running, under these circumstances, the revs increase to meet the new demand for power.)

Hi AndyInOz
Thanks for your message and I hope the summer isn't too awful for you. (I have a friend in Perth who is really struggling!!)
I entirely agree with your x + y, but I'm seeing it slightly differently. In that the "y" component is, initially, provided by the battery, as evidenced by the reduction in range. 5 or 6 miles usually. But then the petrol engine kicks in (almost immediately), presumably also to provide the "y" component. Now that it has taken over the "heavy lifting" from the battery, why don't I get back the 5 or 6 miles of range that I lost in the beginning? It feels as if both the battery AND the ICE are doing the same work?

 

[littlescrote]

Where do you see a one or two kW heater? Typical is six or seven kW for an electric heater. Three kW is not bad for the heat pump. Sure if it isn't cold out the heat pump may get down to two. But if it is sunny out you probably will not be using it anyway at the warmer temperatures.

Use the power monitor in the dash display to monitor power consumption of the climate system and the motors.

I think the PTC heater in the Outlander is 3kW IIRC, but it's not all or nothing.

 

[PHEV07]

Use the power monitor in the dash display to monitor power consumption of the climate system and the motors.

I think the PTC heater in the Outlander is 3kW IIRC, but it's not all or nothing.

Unfortunately the 2023 to 2025 no longer have a PTC Heater. They only have a Heat Pump that works only until the temperature drops to -15'C lower than this, their is no heat for the Cab until the ICE is running and warms up.

2022 and older models do use a PTC Heater and woks well

 

[AndyInOz]

Hi AndyInOz
Thanks for your message and I hope the summer isn't too awful for you. (I have a friend in Perth who is really struggling!!)
I entirely agree with your x + y, but I'm seeing it slightly differently. In that the "y" component is, initially, provided by the battery, as evidenced by the reduction in range. 5 or 6 miles usually. But then the petrol engine kicks in (almost immediately), presumably also to provide the "y" component. Now that it has taken over the "heavy lifting" from the battery, why don't I get back the 5 or 6 miles of range that I lost in the beginning? It feels as if both the battery AND the ICE are doing the same work?

Hiya Barrie1956,

I think that's just a flaw in the guessometer algorithm.

When you select heating etc. it makes a guess something like this:

"Based on the last n kilometres, the current estimated range displayed, and this new demand for power, which I'm assuming will go on for ever, how far can I go?"

When you switch off the heating/cooling the current range displayed has already been lowered, so the calculation fails.

There's an English guy on youtube who raved about this, how when he turns on the heater, he instantly, permanently, loses five miles off his range.

Of course, he doesn't. He's looking at a guess, and the guess doesn't cope very well with changing conditions.

I've mentioned before how the guess-ometer worked on my brother's Holden (Vauxhall/Chevrolet)

He towed a rain water tank out to an air-field (huge wind resistance while towing) on the way home, towing the now empty trailer, his guess-ometer was continually increasing his range remaining, as if the car was manufacturing fuel for the entire journey. Clearly that indicates that the range estimate (AKA guess) was some kind of average between the current journey and the previous journey.

I'm guessing that we'd 'recover' the missing range, if we turned the heater off, pulled over, stopped and restarted the car's electronics forcing a new calculation from scratch.



PS. Thanks for the good wishes, we've had a mild summer so far, with no days over 40° C.
February is typically the hottest month of the year for us, so we may still have some hot weather to come.

 

[Barrie1956]

Hiya Barrie1956,

I think that's just a flaw in the guessometer algorithm.

When you select heating etc. it makes a guess something like this:

"Based on the last n kilometres, the current estimated range displayed, and this new demand for power, which I'm assuming will go on for ever, how far can I go?"

When you switch off the heating/cooling the current range displayed has already been lowered, so the calculation fails.

There's an English guy on youtube who raved about this, how when he turns on the heater, he instantly, permanently, loses five miles off his range.

Of course, he doesn't. He's looking at a guess, and the guess doesn't cope very well with changing conditions.

I've mentioned before how the guess-ometer worked on my brother's Holden (Vauxhall/Chevrolet)

He towed a rain water tank out to an air-field (huge wind resistance while towing) on the way home, towing the now empty trailer, his guess-ometer was continually increasing his range remaining, as if the car was manufacturing fuel for the entire journey. Clearly that indicates that the range estimate (AKA guess) was some kind of average between the current journey and the previous journey.

I'm guessing that we'd 'recover' the missing range, if we turned the heater off, pulled over, stopped and restarted the car's electronics forcing a new calculation from scratch.



PS. Thanks for the good wishes, we've had a mild summer so far, with no days over 40° C.
February is typically the hottest month of the year for us, so we may still have some hot weather to come.

Hi Andy
Thanks for your reply. I reckon you have hit the nail on the head, with the "guess-o-meter". No doubt, I've been crediting it with too much "intelligence" and accuracy. Seeing it for what it really is does make it easier for me to come to terms with the "lost" mileage. It will still bug me, but I'll get over it.
Cheers!!