[HighlandPete]

Originally Posted by Burnzie’s BM

Where the F has the 4 miles gone in the 2 minutes chat?

Ignition turn off - 23 miles
2 minute chat
Get back in the car - 19 miles

Yes I get that it’s cold outside and range will be effected but how can it reduce the range by 4 miles sitting there doing nothing.

It can’t be pre heating the car, nothing was left on, everything off and locked.

I suspect it is calculating in a more advanced way than you will expect to be popping up on the screen. Particularly when there are interruptions in the drive pattern.

Say it is allowing for the first start heating pattern, and the 'draw' tailing off as you drive distance. You then interrupt and have a restart. It is probably recalculated to 'reheat' the cabin, and associated losses, which naturally knocks off some mileage range. Do you recover some mileage, if you then continue to drive a decent distance?

Keep in mind EV is not just about mileage, it has to include the demands of onboard systems, as part of the calculations. Wh/mile must include both factors.

[Burnzie’s BM]

Originally Posted by Jkwon

It based it off of the most recent journey, lots of stop start will reduce the estimation of range. The battery (motor) is most efficient when used for constant speed driving. If you reset your mpg before driving 0.3miles in an ice car you would see dramatically poor mpg aswell

I get the estimated range based on recent journey but this should be taken in to account on the starting electric range figure, not after I’ve traveled .3 of a mile surely?

So for the short. .3 mile journey from start in the morning to the childminder would be better done in petrol mode rather than hybrid or electric?

To add: in that very short journey I stop once at a junction the rest is through a 20mph zone.

Apologies if I’m sounding thick as mince but no other cars had me scratching my head as much as this one.

[Chuckyarla]

Started with a full charge this morning, have driven 19 kms and it shows a range of 8 kms left. That's 27 kms total or 16.7 miles. Driving real easy I Hybrid mode. What am I doing wrong???

[HighlandPete]

Originally Posted by Chuckyarla

Started with a full charge this morning, have driven 19 kms and it shows a range of 8 kms left. That's 27 kms total or 16.7 miles. Driving real easy I Hybrid mode. What am I doing wrong???

Are you pre-conditioning the car and battery before driving off. What I'm reading, there is no chance to hold the full charge (or range) on a 10amp supply.

As I see it, if the cabin needs any heat, (besides electric seat heating etc.), you are on a looser, before you even start.

BTW, what was the ambient temperature?

[Chuckyarla]

No I didn’t pre-heat. I did turn on the heated seat briefly after starting. Ambient temperature 5c.

[HighlandPete]

Originally Posted by Chuckyarla

No I didn’t pre-heat. I did turn on the heated seat briefly after starting. Ambient temperature 5c.

Get it, both the cold cabin and ambient temperature are against you.

I look at in a very simplistic way, trying to get my data together, to see if a 330e touring will cope with my driving profile.

You have 10.4kWh usable capacity from the battery pack, fully charged.

Your heating system 'electric' heater can draw up to 5.5kWh +/- 10%.

Say fully charged, you have a range of 30 miles and you intend to drive at 30mph. Without any 'consumer' demands, you should get that mileage, give or take a couple of miles (depending on the benefit of any regeneration), if you drive until the battery reads ---.

Now add the HVAC demands from a cold start. Say it immediately draws 5.2kWh for cabin heat. You drive for 20 minutes and 10 miles (at 30mph). Let's assume the cabin is just coming up to the setting temperature, (probably realistic at 5°C), the electric element is about to back off its demand, but you stop. Instead of the predicted range of 30miles, you have in that short distance of 10 miles, used half the battery capacity. You now have a 10 mile projected range, based on real time data. Giving a total of 20 miles.

Hopefully the range will extend, as the energy demand per mile decreases over the next 10 miles, if you were to drive it in one trip.

My reasoning based on the following:

Drive: 10.4 kWh over 30 miles. 10 miles @ 347 Wh/mile = 3.47 kWh
Heating: 5.2 kWh over 30 miles. 20 minutes @ 173 Wh/mile = 1.73 kWh
Total energy demand: 5.2 kWh for 10 miles.

[Chuckyarla]

Ok! So should I preheat or do it on the move?

[HighlandPete]

Originally Posted by Chuckyarla

Ok! So should I preheat or do it on the move?

Definitely do it on the 'mains', if you want to maintain the highest possible EV range.

The charging rate is my dilemma. 10amps from an external wall socket already installed, (my home), won't fully pre-condition in cold weather, will still deplete the battery to some degree. I've got plenty of time to charge the battery, but not the capacity to fully pre-condition, without an extra power supply.

The electric heater alone, (not including seats) can draw up to 21amps.

[Jkwon]

Originally Posted by BurnzieÂ’s BM

I get the estimated range based on recent journey but this should be taken in to account on the starting electric range figure, not after I’ve traveled .3 of a mile surely?

So for the short. .3 mile journey from start in the morning to the childminder would be better done in petrol mode rather than hybrid or electric?

To add: in that very short journey I stop once at a junction the rest is through a 20mph zone.

Apologies if I’m sounding thick as mince but no other cars had me scratching my head as much as this one.

I would imagine that your journey home is longer than 0.3m so overnight after a charge it's anticipating a longer journey, it then does 0.3 miles and decided it can't do 30 miles worth in that fashion. All I can say is I did a journey yesterday, over 120 miles and achieved 60 miles in electric total (30 before the engine kicked in and the majority of that was m25/a21 so 60-70mph) I think the car is more efficient in electric only mode than running in hybrid for electric range. I can't understand it

[HighlandPete]

Originally Posted by Jkwon

I would imagine that your journey home is longer than 0.3m so overnight after a charge it's anticipating a longer journey, it then does 0.3 miles and decided it can't do 30 miles worth in that fashion. All I can say is I did a journey yesterday, over 120 miles and achieved 60 miles in electric total (30 before the engine kicked in and the majority of that was m25/a21 so 60-70mph)...

That's how I see it. It must recalculate to give a projected range on the current data available. Continue to drive and it will readjust accordingly.

[KrisJ]

Originally Posted by HighlandPete

Get it, both the cold cabin and ambient temperature are against you.

I look at in a very simplistic way, trying to get my data together, to see if a 330e touring will cope with my driving profile.

You have 10.4kWh usable capacity from the battery pack, fully charged.

Your heating system 'electric' heater can draw up to 5.5kWh +/- 10%.

Say fully charged, you have a range of 30 miles and you intend to drive at 30mph. Without any 'consumer' demands, you should get that mileage, give or take a couple of miles (depending on the benefit of any regeneration), if you drive until the battery reads ---.

Now add the HVAC demands from a cold start. Say it immediately draws 5.2kWh for cabin heat. You drive for 20 minutes and 10 miles (at 30mph). Let's assume the cabin is just coming up to the setting temperature, (probably realistic at 5°C), the electric element is about to back off its demand, but you stop. Instead of the predicted range of 30miles, you have in that short distance of 10 miles, used half the battery capacity. You now have a 10 mile projected range, based on real time data. Giving a total of 20 miles.

Hopefully the range will extend, as the energy demand per mile decreases over the next 10 miles, if you were to drive it in one trip.

My reasoning based on the following:

Drive: 10.4 kWh over 30 miles. 10 miles @ 347 Wh/mile = 3.47 kWh
Heating: 5.2 kWh over 30 miles. 20 minutes @ 173 Wh/mile = 1.73 kWh
Total energy demand: 5.2 kWh for 10 miles.

That is not how yoy calculate these things. There is a difference between KWh (an amount of energy) and KW (a rate of energy consumption).

If I drive my car gently, mixed local and highway and never exceeding 110 kph, it will do 18.4 to 20.1 KWh/100 km

If the full 12KWh of battery would be available for driving I would therefore get 65 to 60 km of range.

Usually though I can get 39 to 42 km of full electric driving on days where it is 8 to 10 degC.

Why?

1) if the cabin heater draws 3000 W (which is hefty) it would consume 3KWh in an hours drive.
2) even when the GOM indicates no range left, the car continues to drive all electric because all EVs apply some kind of 'bottom buffer' as completely depleting the battery is bad for its longevity.
3) likely the battery also has a top buffer (see Bjørn Nyland on YouTube) as also fully charging a battery is not the best.

Long story short, I would guess there are only ever 9 to 10 KWh of battery available for electric driving... Probably closer to 9 than to 10.

Also not how the GOM really increases the range if you have a longer downhill section and decreases if you do a sharp acceleration in Hybrid mode ( electric assists the ice)

[Cranester1983]

Why isn’t the full power of the battery available for use? Does the car not have a regular on board car battery available for use?

[HighlandPete]

Originally Posted by KrisJ

That is not how yoy calculate these things. There is a difference between KWh (an amount of energy) and KW (a rate of energy consumption).

If I drive my car gently, mixed local and highway and never exceeding 110 kph, it will do 18.4 to 20.1 KWh/100 km

If the full 12KWh of battery would be available for driving I would therefore get 65 to 60 km of range.

Usually though I can get 39 to 42 km of full electric driving on days where it is 8 to 10 degC.

Why?

1) if the cabin heater draws 3000 W (which is hefty) it would consume 3KWh in an hours drive.
2) even when the GOM indicates no range left, the car continues to drive all electric because all EVs apply some kind of 'bottom buffer' as completely depleting the battery is bad for its longevity.
3) likely the battery also has a top buffer (see Bjørn Nyland on YouTube) as also fully charging a battery is not the best.

Long story short, I would guess there are only ever 9 to 10 KWh of battery available for electric driving... Probably closer to 9 than to 10.

Also not how the GOM really increases the range if you have a longer downhill section and decreases if you do a sharp acceleration in Hybrid mode ( electric assists the ice)

I'm not sure you read my post, what I termed a 'very simplistic way' of working out where the energy is going.

I simply posed one simple scenario. The finer detail of the 'variables', I concluded, was not going to help.

BTW, BMW claim 10.4kWh of the battery pack is usable energy. The electric heater unit consumption figure is also from BMW's technical data.

[HighlandPete]

Originally Posted by Cranester1983

Why isn’t the full power of the battery available for use? Does the car not have a regular on board car battery available for use?

It may be a 12kWh battery pack, but only 10.4kWh is rated as 'usable' energy.

[Cranester1983]

Originally Posted by HighlandPete

It may be a 12kWh battery pack, but only 10.4kWh is rated as 'usable' energy.

Why?

[tricky6]

Originally Posted by HighlandPete

Thanks, but no hurry.

So at 60mph mine ranges from 4-5 miles/kw which would imply circa 50mile range... But only when on the flat of course... Given that I can get 32-35 miles in the real world that would seem about right. It never lets you use the whole 12kW battery anyway.

[KrisJ]

Originally Posted by Cranester1983

Why?

Because the battery isn't allowed to drain completely and because likely, they don't let you charge it to the real maximum SoC, that way they can mask degradation of the battery over time...

Finally, some battery capacity is going to HVAC.

[IMG]https://is.gd/BLPDQN[/IMG]


https://fullycharged.show/blog/surpr...-depreciation/

[KrisJ]

Originally Posted by HighlandPete

I'm not sure you read my post, what I termed a 'very simplistic way' of working out where the energy is going.

I simply posed one simple scenario. The finer detail of the 'variables', I concluded, was not going to help.

BTW, BMW claim 10.4kWh of the battery pack is usable energy. The electric heater unit consumption figure is also from BMW's technical data.

My point was that your post mixes the meaning of the physical quantities 'Power' which is expressed in Watts and 'Energy', expressed in Watt hours.

A heating system cannot draw 5.5 KWh. It could draw 5.5 kW and if you would run it for an hour, it would consume 5.5 kWh.

You can only make sensible estimates of physical things if you use correct units

[HighlandPete]

Originally Posted by KrisJ

You can only make sensible estimates of physical things if you use correct units

Ah, I need to drop a couple of H's.

[Cranester1983]

Originally Posted by KrisJ

Because the battery isn't allowed to drain completely and because likely, they don't let you charge it to the real maximum SoC, that way they can mask degradation of the battery over time...

Finally, some battery capacity is going to HVAC.

[IMG]https://is.gd/BLPDQN[/IMG]


https://fullycharged.show/blog/surpr...-depreciation/

Is there not a regular car battery on board?

[tricky6]

Originally Posted by HighlandPete

It may be a 12kWh battery pack, but only 10.4kWh is rated as 'usable' energy.

I've got 11.5Kw of charge into mine before and have seen it down as low as 6% so I reckon there is a little bit more available

[HighlandPete]

Originally Posted by tricky6

I've got 11.5Kw of charge into mine before and have seen it down as low as 6% so I reckon there is a little bit more available

11.5 kWh, is that the figure from the grid, or stored in the batteries?

You have to take Charging Efficiency into consideration. Remember there are energy losses, both from the charger and the battery cells. Together, can account for a higher figure.