Battery and range

[Chris]

This month the car is showing 3.2 miles per kw but if I look at my electric usage it’s 3.0 miles per kw, based on just over 1000 miles that’s around 21 kw difference for pre heating and loses

[sidehaas]

Okay, so today the car had been parked overnight at -4C and was caked with ice. I had to use the electrical windscreen and rear windscreen heaters for about 10 minutes to clear the ice with the car parked before driving 21 miles in to work. According to the dashboard this was running pasked at about 5kW to clear ice but it dropped to 0.5kWh when I turned them off, with the car in gear. The total journey economy came in at 3.7 mi/kWh, down from 4.5 mi/kWh and the lowest I have ever seen so maybe this is the lower consumption over people are seeing. I have only had the car for a month so I am learning but I can see nothing to support the "warm the battery" theory, there wasn't any power drain for that and the chemistry professor I asked thought that was rubbish. The battery should slowly heat itself through use. The power drain from freezing all depended on what heating I have on. I also think if you are seeing much less than an average of 4.5 once you are actually driving (or when you don't need to de-ice) either you are heating the cabin deliberately or accidentally (it took me a while to work out how to turn that all off; it is completely not needed for comfort) or you are driving like a teenager.

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

[monkeyhanger]

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

How does the car determine you're going to undertake a short journey?

Whether an ID3 on 2.0, 2.1 or 2.3, or a Born on 3.0, my winter short journey efficiency has been crap. The 2 mile school run barely makes it to 2.2 miles per kWh, with no heating, or 1.8 miles per kWh with some heating (to 16C) with an ambient temp 2 to 4C. Same journey in the Summer is about 4 miles per kWh. For that very short journey in temps approaching zero, the battery heating is very active and pulling about as much juice as moving the car takes. There doesn't seem to be a lower speed threshold that avoids that battery heating, unless it's under 20mph.

The amount of battery warming needed does tail off when you approach 20 miles when it's really cold and seems to be non-existent when ambient temp is about 14C. The further you drive on a journey, the lower the effect of battery heating. In my old 31 mile commute almost all at 70mph on a dual carriageway, it was an easy 3.7 miles per kWh in the Summer and about 3.1 miles at around 4C, so far less of a hit than the 2 mile school run.

[sidehaas]

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

How does the car determine you're going to undertake a short journey?

Whether an ID3 on 2.0, 2.1 or 2.3, or a Born on 3.0, my winter short journey efficiency has been crap. The 2 mile school run barely makes it to 2.2 miles per kWh, with no heating, or 1.8 miles per kWh with some heating (to 16C) with an ambient temp 2 to 4C. Same journey in the Summer is about 4 miles per kWh. For that very short journey in temps approaching zero, the battery heating is very active and pulling about as much juice as moving the car takes. There doesn't seem to be a lower speed threshold that avoids that battery heating, unless it's under 20mph.

The amount of battery warming needed does tail off when you approach 20 miles when it's really cold and seems to be non-existent when ambient temp is about 14C. The further you drive on a journey, the lower the effect of battery heating. In my old 31 mile commute almost all at 70mph on a dual carriageway, it was an easy 3.7 miles per kWh in the Summer and about 3.1 miles at around 4C, so far less of a hit than the 2 mile school run.

I don't know how it determines when to start battery heating. It could be prompted by time, distance, speed, motor power or some combination of the above, together with temperatures and maybe SoC.
I'm amazed what you say about short journey efficiency with heating off. I get 4m/kwh on a school run even now (it's 20-30mph). Last year (car built with 2.3, never did battery heating on the driveway) I got up to 3.5mi/kwh, software 3.0 seems to have improved it a bit further. If I turn on cabin heating for that length f journey it drops to <2mi/kWh. Battery heating is not involved at all (Edit: or if it is, then it's not a significant contributor and it's contribution to consumption isn't visible when the car is stopped either before or during a journey).
Either our cars are different, or you are driving 2 miles along a motorway, or it's accounting for energy input preheating before you set off.
(My car is certainly not special, on the motorway I regularly see <3 in the winter and my long term average since 3.0 OTA a month ago is 3.2mi/kWh. But short journeys are easily highest efficiency if cabin heating is off. This is absolutely consistent behaviour over last winter and this, although I recognise that last winter most cars with older software were behaving differently).

[Scratch]

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

How does the car determine you're going to undertake a short journey?

Whether an ID3 on 2.0, 2.1 or 2.3, or a Born on 3.0, my winter short journey efficiency has been crap. The 2 mile school run barely makes it to 2.2 miles per kWh, with no heating, or 1.8 miles per kWh with some heating (to 16C) with an ambient temp 2 to 4C. Same journey in the Summer is about 4 miles per kWh. For that very short journey in temps approaching zero, the battery heating is very active and pulling about as much juice as moving the car takes. There doesn't seem to be a lower speed threshold that avoids that battery heating, unless it's under 20mph.

The amount of battery warming needed does tail off when you approach 20 miles when it's really cold and seems to be non-existent when ambient temp is about 14C. The further you drive on a journey, the lower the effect of battery heating. In my old 31 mile commute almost all at 70mph on a dual carriageway, it was an easy 3.7 miles per kWh in the Summer and about 3.1 miles at around 4C, so far less of a hit than the 2 mile school run.

I don't know how it determines when to start battery heating. It could be prompted by time, distance, speed, motor power or some combination of the above, together with temperatures and maybe SoC.
I'm amazed what you say about short journey efficiency with heating off. I get 4m/kwh on a school run even now (it's 20-30mph). Last year (car built with 2.3, never did battery heating on the driveway) I got up to 3.5mi/kwh, software 3.0 seems to have improved it a bit further. If I turn on cabin heating for that length f journey it drops to <2mi/kWh. Battery heating is not involved at all (Edit: or if it is, then it's not a significant contributor and it's contribution to consumption isn't visible when the car is stopped either before or during a journey).
Either our cars are different, or you are driving 2 miles along a motorway, or it's accounting for energy input preheating before you set off.
(My car is certainly not special, on the motorway I regularly see <3 in the winter and my long term average since 3.0 OTA a month ago is 3.2mi/kWh. But short journeys are easily highest efficiency if cabin heating is off. This is absolutely consistent behaviour over last winter and this, although I recognise that last winter most cars with older software were behaving differently).

Has anybody asked if the cars in question have heat pumps or not? Ours has a heat pump, mostly short journeys (about 12 miles), varied speed limits between 20 and 60mph. Our efficiency is about 3.1 miles/kWh. in these current temperatures.

[sidehaas]

No heat pump here.
Worth noting the heat pump only affects cabin heating.

[Scratch]

No heat pump here.
Worth noting the heat pump only affects cabin heating.

Yes it does only heat the cabin, but that means that the main drive battery doesn't have to.

[sidehaas]

No heat pump here.
Worth noting the heat pump only affects cabin heating.

Yes it does only heat the cabin, but that means that the main drive battery doesn't have to.

The battery runs the heat pump. It uses less energy than running a resistive electric heater, which is what the heat pump replaces.
If/when the battery itself requires heating, regardless of whether the car has a heat pump, it uses an electric heater to warm the coolant at battery inlet. That itself obviously uses energy from the battery.

[andrewtc]

Okay, so today the car had been parked overnight at -4C and was caked with ice. I had to use the electrical windscreen and rear windscreen heaters for about 10 minutes to clear the ice with the car parked before driving 21 miles in to work. According to the dashboard this was running pasked at about 5kW to clear ice but it dropped to 0.5kWh when I turned them off, with the car in gear. The total journey economy came in at 3.7 mi/kWh, down from 4.5 mi/kWh and the lowest I have ever seen so maybe this is the lower consumption over people are seeing. I have only had the car for a month so I am learning but I can see nothing to support the "warm the battery" theory, there wasn't any power drain for that and the chemistry professor I asked thought that was rubbish. The battery should slowly heat itself through use. The power drain from freezing all depended on what heating I have on. I also think if you are seeing much less than an average of 4.5 once you are actually driving (or when you don't need to de-ice) either you are heating the cabin deliberately or accidentally (it took me a while to work out how to turn that all off; it is completely not needed for comfort) or you are driving like a teenager.

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

Ok, now that is possible. I will see it I can think of a way to test it. Probably part of the better efficiency is because at work it is parked on a trickle charger so probably when I set off home it already has a warm battery from the waste heat of charging. But in the morning on the way in thats not true. As I say, am still trying to figure it all out.

[sidehaas]

Okay, so today the car had been parked overnight at -4C and was caked with ice. I had to use the electrical windscreen and rear windscreen heaters for about 10 minutes to clear the ice with the car parked before driving 21 miles in to work. According to the dashboard this was running pasked at about 5kW to clear ice but it dropped to 0.5kWh when I turned them off, with the car in gear. The total journey economy came in at 3.7 mi/kWh, down from 4.5 mi/kWh and the lowest I have ever seen so maybe this is the lower consumption over people are seeing. I have only had the car for a month so I am learning but I can see nothing to support the "warm the battery" theory, there wasn't any power drain for that and the chemistry professor I asked thought that was rubbish. The battery should slowly heat itself through use. The power drain from freezing all depended on what heating I have on. I also think if you are seeing much less than an average of 4.5 once you are actually driving (or when you don't need to de-ice) either you are heating the cabin deliberately or accidentally (it took me a while to work out how to turn that all off; it is completely not needed for comfort) or you are driving like a teenager.

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

Ok, now that is possible. I will see it I can think of a way to test it. Probably part of the better efficiency is because at work it is parked on a trickle charger so probably when I set off home it already has a warm battery from the waste heat of charging. But in the morning on the way in thats not true. As I say, am still trying to figure it all out.

It's extremely difficult to work out when it's heating, unless you have an older software car which will do it when you are sat still with cabin heating off: at that point you know it's battery heating if you can still see significant consumption. Otherwise the only reliable way is to get an obd dongle and carscanner, then look at the 'battery inlet' temperature reading. This is the coolant temperature. When the battery is being heated it shoots up.

[andrewtc]

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

Ok, now that is possible. I will see it I can think of a way to test it. Probably part of the better efficiency is because at work it is parked on a trickle charger so probably when I set off home it already has a warm battery from the waste heat of charging. But in the morning on the way in thats not true. As I say, am still trying to figure it all out.

It's extremely difficult to work out when it's heating, unless you have an older software car which will do it when you are sat still with cabin heating off: at that point you know it's battery heating if you can still see significant consumption. Otherwise the only reliable way is to get an obd dongle and carscanner, then look at the 'battery inlet' temperature reading. This is the coolant temperature. When the battery is being heated it shoots up.

Ok. When it is parked it displays “kWh/h” which seems to be about 0.4 most of the time. It only goes up when the cabin heating is on (up to about 5) but the VW website has comments about heating your battery using the air conditioning so the battery heater, if there is one, may be kind of combined? Having underground parking with a charger at work seems to be luckier than I thought though.

[andrewtc]

How does the car determine you're going to undertake a short journey?

Whether an ID3 on 2.0, 2.1 or 2.3, or a Born on 3.0, my winter short journey efficiency has been crap. The 2 mile school run barely makes it to 2.2 miles per kWh, with no heating, or 1.8 miles per kWh with some heating (to 16C) with an ambient temp 2 to 4C. Same journey in the Summer is about 4 miles per kWh. For that very short journey in temps approaching zero, the battery heating is very active and pulling about as much juice as moving the car takes. There doesn't seem to be a lower speed threshold that avoids that battery heating, unless it's under 20mph.

The amount of battery warming needed does tail off when you approach 20 miles when it's really cold and seems to be non-existent when ambient temp is about 14C. The further you drive on a journey, the lower the effect of battery heating. In my old 31 mile commute almost all at 70mph on a dual carriageway, it was an easy 3.7 miles per kWh in the Summer and about 3.1 miles at around 4C, so far less of a hit than the 2 mile school run.

I don't know how it determines when to start battery heating. It could be prompted by time, distance, speed, motor power or some combination of the above, together with temperatures and maybe SoC.
I'm amazed what you say about short journey efficiency with heating off. I get 4m/kwh on a school run even now (it's 20-30mph). Last year (car built with 2.3, never did battery heating on the driveway) I got up to 3.5mi/kwh, software 3.0 seems to have improved it a bit further. If I turn on cabin heating for that length f journey it drops to <2mi/kWh. Battery heating is not involved at all (Edit: or if it is, then it's not a significant contributor and it's contribution to consumption isn't visible when the car is stopped either before or during a journey).
Either our cars are different, or you are driving 2 miles along a motorway, or it's accounting for energy input preheating before you set off.
(My car is certainly not special, on the motorway I regularly see <3 in the winter and my long term average since 3.0 OTA a month ago is 3.2mi/kWh. But short journeys are easily highest efficiency if cabin heating is off. This is absolutely consistent behaviour over last winter and this, although I recognise that last winter most cars with older software were behaving differently).

Has anybody asked if the cars in question have heat pumps or not? Ours has a heat pump, mostly short journeys (about 12 miles), varied speed limits between 20 and 60mph. Our efficiency is about 3.1 miles/kWh. in these current temperatures.

I didn’t get the heat pump. But i like driving cold, it keeps me awake. The “since purchase” economy of my car is down to 4.2 but there is a lot of experimentation and a couple of motorway journeys in that. I was getting 4.5 to work but it is definitely lower on icy journeys. About 3.7 into work from frozen and 4 home.

[OB1CCFC]

Tbh in my new Niro EV with its ‘fabled’ efficiency I am struggling to get over 3 mi/kWh on short runs right now, even a 30 mile round trip to the airport with heating on 21 degs C a fair amount of the time didn’t make 3!
I’m of the opinion that’s just how these batteries are and you can wrap it in all the algorithms and smoke and mirrors you like- it won’t make much difference.

[PeterA2001]

I’ve only just got mine, a 1st edition, until the car I’ve ordered arrives.
Whilst I’ve seen a high of 3.9 mi I’m usually in high two’s but sometimes low. Im putting it down to the weather albeit the high came on the coldest day so far. I’d pre-heated it and so the range dropped but then stayed steady for the actual journey. I’m still learning this electric car thing and think I’ll focus more on the percentage than the range that goes up and down. I tried the Tesla chargers today. First time public charging away from work. It worked perfectly fine though I felt guilty having to take two spaces. Just about got away with it. It seems Tesla, Polestar, Land Rover and Vauxhall etc have the socket on the left, VW on the right. From what I witnessed anyway.

[sidehaas]

The car heats the battery but with later software versions it doesn't do it when sat on the drive or for short slow journeys.

How does the car determine you're going to undertake a short journey?

Whether an ID3 on 2.0, 2.1 or 2.3, or a Born on 3.0, my winter short journey efficiency has been crap. The 2 mile school run barely makes it to 2.2 miles per kWh, with no heating, or 1.8 miles per kWh with some heating (to 16C) with an ambient temp 2 to 4C. Same journey in the Summer is about 4 miles per kWh. For that very short journey in temps approaching zero, the battery heating is very active and pulling about as much juice as moving the car takes. There doesn't seem to be a lower speed threshold that avoids that battery heating, unless it's under 20mph.

The amount of battery warming needed does tail off when you approach 20 miles when it's really cold and seems to be non-existent when ambient temp is about 14C. The further you drive on a journey, the lower the effect of battery heating. In my old 31 mile commute almost all at 70mph on a dual carriageway, it was an easy 3.7 miles per kWh in the Summer and about 3.1 miles at around 4C, so far less of a hit than the 2 mile school run.

I don't know how it determines when to start battery heating. It could be prompted by time, distance, speed, motor power or some combination of the above, together with temperatures and maybe SoC.
I'm amazed what you say about short journey efficiency with heating off. I get 4m/kwh on a school run even now (it's 20-30mph). Last year (car built with 2.3, never did battery heating on the driveway) I got up to 3.5mi/kwh, software 3.0 seems to have improved it a bit further. If I turn on cabin heating for that length f journey it drops to <2mi/kWh. Battery heating is not involved at all (Edit: or if it is, then it's not a significant contributor and it's contribution to consumption isn't visible when the car is stopped either before or during a journey).
Either our cars are different, or you are driving 2 miles along a motorway, or it's accounting for energy input preheating before you set off.
(My car is certainly not special, on the motorway I regularly see <3 in the winter and my long term average since 3.0 OTA a month ago is 3.2mi/kWh. But short journeys are easily highest efficiency if cabin heating is off. This is absolutely consistent behaviour over last winter and this, although I recognise that last winter most cars with older software were behaving differently).

I just generated some real data at lunchtime to illustrate what I wrote above. I needed to do a short return trip to pick something up. No altitude change, 3.5 miles each way, the car hadn't been driven much or charged earlier in the day, outside temperature 1-1.5C.

First image is after driving there, 30-40mph with a delay for some roadworks. ACC at 20C.
Second image is after driving back, identical trip with a slightly shorter queue for the roadworks. ACC off except for steering wheel heater.
2.1mi/kWh Vs 4.5mi/kWh. To reiterate this is all down to cabin heating (software 3.0), on a journey of this length and type. The difference is much less on a motorway journey because cabin heating is a much smaller proportion of total consumption and because the cabin has longer to reach the set temperature.
To check there was no battery heating effect, while I was sat in the roadworks queue on the way there, I briefly reduced the set cabin temperature from 20 to LO, which reduced consumption from ~3kw to 0.6-0.7kw. I then put it up to HI, which increased consumption to ~4.8kw. I then put it back to 20 and it reduced back to ~3kw. So as you can see this is all about cabin temp and has nothing to do with battery heating. The battery heating must only initiate once power, speed or journey time exceed some limit.

[Chris]

I think you’d need to do this on a longer run and maybe heating on on the return trip and none on the first

I can regular make journeys where one way is really efficient and the other way isn’t with no change in temperature, traffic could be lighter not as many stops or just driving up hills vs driving down

We all know that cabin heating is bad for the range but if you turned your heating fully off and you achieved 4.5 miles on the stats you still won’t get 260 miles range from the car because even in version 3 short journeys using the battery but not showing this in the stats

[sidehaas]

I think you’d need to do this on a longer run and maybe heating on on the return trip and none on the first

I can regular make journeys where one way is really efficient and the other way isn’t with no change in temperature, traffic could be lighter not as many stops or just driving up hills vs driving down

We all know that cabin heating is bad for the range but if you turned your heating fully off and you achieved 4.5 miles on the stats you still won’t get 260 miles range from the car because even in version 3 short journeys using the battery but not showing this in the stats

The results for a longer journey would be very different. My aim here was to illustrate what I said previously which is that on short, modest speed journeys with cars on newer software versions, no battery heating occurs but consumption is still very poor if you have cabin heating on, but it is very good if cabin heating is off.
On a longer motorway journey, the cabin heating consumption reduces quite a bit once the car is up to temperature (you might also preheat), while other consumption types increase a lot - mainly motor usage at high speed,but also probably battery heating at some point (probably triggered by either time, speed or power level I think, but this information has not been released by VW, they have only said it is introduced in a staggered way.)
As a result the effect of cabin temperature setting on long journey real range is modest, but the effect on short journey consumption (and therefore also GOM predicted range before setting off on a longer journey) is huge.
This is the source of quite a few concerned posts you see from people going through their first winter.