High consumption after first start

[or1]

I agree if you are ‘on it’, heavy acceleration and heavy braking recuperation is significant. It probably extends range for a full charge on a track day by 10%. From 100 miles to 110.

When people talk about extending range they want high range when road tripping and cruising. The range people want is getting near to 300 miles as (im)possible.

To achieve these maximum ranges recuperation is (almost) entirely irrelevant. It is completely a false hope that new Taycan drivers will experience a huge leap in range once the discs and pads have bedded in and recuperation starts.

The best example for me is driving up a mountain. It takes way more electric energy going up than can be recuperated from the potential energy of altitude coming down.

As an experiment I drove up an Alpine Rd from Grenoble to a ski station. I hardly touched the brakes. I used 20%.

35k 22 miles - 1300 metre 4000 ft

I coasted down the mountain and hardly touched the accelerator. I recuperated 4%. I had optimistically charged to only 80% in the ski station hoping for a load of free energy. I was disappointed

Although of course my battery had to heat up as it was morning, cold and not preheated. On the way up the mountain my battery was purring away at optimal temperature as we had cruised from Dijon to Grenoble. 300k.

It is battery temperature that is the key. Cabin temperature is directly link to battery temperature as this is where the heat is scavenged from.

You must of course have a Heat Pump to have any chance of good consumption and range in the cold.
This is not standard everywhere although surprisingly is in UK where Porsche are much meaner than in USA with ‘freebies’

Interesting numbers for going up and down.

Positional energy itself is about 0,28 kWh per ton per 100 meters height (at or around sea level). A Taycan, say 2,5 tons with load, lifted 1300 meters should consume 2,5 x 13 x 0,28 kWh = 9,1 kWh for that part of the job – actually a bit more because motors etc are not 100% efficient, so say 10 kWh or 12% of the battery capacity. The other 8% of battery you used were for overcoming rolling and air resistance, heating/cooling etc. 8% battery is around 6,7 kWh, and divided by 22 miles consumption is 30 kWh/100 miles for that. Not unreasonable.

If you went down with about the same speed and the same air temperature as going up, consumption «as if flat» might be around the same 8% of battery. But you ended up with 4% gained in battery, e.g. regen was around 12% of battery, or the same that went in as positional energy gain going up.

This is not to prove that regen is 100% efficient. It isn’t. Some of the presumptions in my calculation are obviously too simple. But regen is significant when it is used sensibly.

On flat terrain on a good road where constant speed can be held, regen is NOT efficient, does not reduce consumption and is best avoided.

Sponsored

 

[Ross]

Interesting numbers for going up and down.

Positional energy itself is about 0,28 kWh per ton per 100 meters height (at or around sea level). A Taycan, say 2,5 tons with load, lifted 1300 meters should consume 2,5 x 13 x 0,28 kWh = 9,1 kWh for that part of the job – actually a bit more because motors etc are not 100% efficient, so say 10 kWh or 12% of the battery capacity. The other 8% of battery you used were for overcoming rolling and air resistance, heating/cooling etc. 8% battery is around 6,7 kWh, and divided by 22 miles consumption is 30 kWh/100 miles for that. Not unreasonable.

If you went down with about the same speed and the same air temperature as going up, consumption «as if flat» might be around the same 8% of battery. But you ended up with 4% gained in battery, e.g. regen was around 12% of battery, or the same that went in as positional energy gain going up.

This is not to prove that regen is 100% efficient. It isn’t. Some of the presumptions in my calculation are obviously too simple. But regen is significant when it is used sensibly.

On flat terrain on a good road where constant speed can be held, regen is NOT efficient, does not reduce consumption and is best avoided.

Agreed.
That’s a wonderful in depth analysis professor!
Above the pay grade of a dentist. I last studied physics at school (1984!)

The going down the mountain bit is fun holding as much speed round the corners as possible otherwise you have to accelerate between hairpins to keep up with traffic which of course out ways any gains you might make from regen.

Mostly coasting. Still fun to drive for 30k and gain energy. Like getting 2 free litres of fuel.

It just makes me chuckle when people claim regen is so good it is like the Taycan has a perpetual motor. About as much scientific basis as Alchemy!

 

[Gru]

This is exactly the question; Why does your consumption decrease from 80/100 to 40/100 after 10 miles??Why does consumption decrease after first start

I assume the following scenario:
- car is cold
- you enter the car, it wakes up, starts the heater, the lights, the heating seats, the hot air, etc .... resulting in a heater working at max, ie about 10A
- you start driving, but slowly because you exit the garage, driveway, small streets in your neighborhood, so your average speed is low, perhaps 5 to 10 km/h (or mph, it doesn't make a difference)
- heater will soon stop, or works intermittently . It won't warm the battery (unless it's extremely cold) since you don't specify a charging stop soon/nearby
All that will result in a very high consumption in the first km/mi

Take the example below: car was steady for 20mn, i just had the heater working 100% for about 30mn. I lost about 5kWh (from 11:50 to 12:20)
Had I drive 1 km during that time (for instance stuck in traffic), consumption would have been ... 500 kWh/100km ! On the opposite, if i had done 100 km during this time (driving on average 200km/h ...), the extra consumption due to heater would have been negligible, +5kWh/100km

Here an example where i was actually driving: I started the car, next charging stop would be 30mn from there.
From 12:10 to 12:20, heater is at max., I'm downtown, slow avg. speed, consumption goes up to 80 kWh/100 km...
I then reach the highway, speed increases... and consumption goes down because the extra energy from heater is now small (but not insignificant) compared to the one needed by the engine.

I once left CarScanner run all night and didn't see any decrease (phantom or not) of SoC when leaving in the morning.
I believe it's all due to heater and slow avg. speed when taking off.

 

[Kaan34]

I assume the following scenario:
- car is cold
- you enter the car, it wakes up, starts the heater, the lights, the heating seats, the hot air, etc .... resulting in a heater working at max, ie about 10A
- you start driving, but slowly because you exit the garage, driveway, small streets in your neighborhood, so your average speed is low, perhaps 5 to 10 km/h (or mph, it doesn't make a difference)
- heater will soon stop, or works intermittently . It won't warm the battery (unless it's extremely cold) since you don't specify a charging stop soon/nearby
All that will result in a very high consumption in the first km/mi

Take the example below: car was steady for 20mn, i just had the heater working 100% for about 30mn. I lost about 5kWh (from 11:50 to 12:20)
Had I drive 1 km during that time (for instance stuck in traffic), consumption would have been ... 500 kWh/100km ! On the opposite, if i had done 100 km during this time (driving on average 200km/h ...), the extra consumption due to heater would have been negligible, +5kWh/100km

Here an example where i was actually driving: I started the car, next charging stop would be 30mn from there.
From 12:10 to 12:20, heater is at max., I'm downtown, slow avg. speed, consumption goes up to 80 kWh/100 km...
I then reach the highway, speed increases... and consumption goes down because the extra energy from heater is now small (but not insignificant) compared to the one needed by the engine.

I once left CarScanner run all night and didn't see any decrease (phantom or not) of SoC when leaving in the morning.
I believe it's all due to heater and slow avg. speed when taking off.

I think that was a very logical explanation of high consumption.. Heater factor is huge according to your readings…But are you sure Carscanner would show phantom drain even if you had run it all night?

 

[Gru]

I think that was a very logical explanation of high consumption.. Heater factor is huge according to your readings…But are you sure Carscanner would show phantom drain even if you had run it all night?

it should show in the SoC and battery energy when starting that morning.
Last summer I left the car outside for 5 days, in 35°C: it didn't loose not even 1%. And consumption
didn't show irrealistic numbers after that

 

[Gru]

Temp. is expected to be close to 0° C tomorrow morning.
I'll have everything off so heater doesn't start and I'll report the numbers

 

[Kaan34]

Temp. is expected to be close to 0° C tomorrow morning.
I'll have everything off so heater doesn't start and I'll report the numbers

Great thank you

 

[Johann55]

Normal mode will heat the battery up after start to 5°C (42°F). You should rather drive in Range mode, so the battery heating stops at 0°C (32°F).

Drive mode vs. battery temperature:
https://www.taycanforum.com/forum/t...-sport-and-sport-plus.9881/page-2#post-142234

 

[Gru]

Normal mode will heat the battery up after start to 5°C (42°F). You should rather drive in Range mode, so the battery heating stops at 0°C (32°F).

Drive mode vs. battery temperature:
https://www.taycanforum.com/forum/t...-sport-and-sport-plus.9881/page-2#post-142234

I was looking for that chart and couldn't find it. Thank you !

 

[KLHubb]

I find that my battery does not heat, but rather will start at or below ambient, depending on night temps here. As I drive, the battery will slowly warm in proportion to the demand I put on the motor.
It will heat on range planner, when I schedule a trip that is beyond the charge's range.
Cabin heat comes on and is uncorrelated to battery heat.

 

[Gru]

I find that my battery does not heat, but rather will start at or below ambient, depending on night temps here. As I drive, the battery will slowly warm in proportion to the demand I put on the motor.
It will heat on range planner, when I schedule a trip that is beyond the charge's range.
Cabin heat comes on and is uncorrelated to battery heat.

I'll do 2 tests then: one in range mode (tomorrow) and one in Sport plus (the day after) and compare.
That'll be downtown, only a few kms. But it'll clarify if the battery is heated or not depending of the mode

I'll only have to wear a thick coat

 

[Kaan34]

I'll do 2 tests then: one in range mode (tomorrow) and one in Sport plus (the day after) and compare.
That'll be downtown, only a few kms. But it'll clarify if the battery is heated or not depending of the mode

I'll only have to wear a thick coat

Looking forward to see the results

 

[Gru]

Looking forward to see the results

first test this morning
- car didn’t move for 48hrs, parked outside. Battery temperature was at outside temperature (4°C). both temperatures didn’t change during this short trip (<10km)
- no preheat, no heated seat, no AC, no music, no sport sound, … only headlights needed

- started the car in range mode. drove for about 3km, then stopped to buy croissants () for 7mn, and drove again. see below.

- heater didn’t start, heater fluid stayed at 5°. short trip consumption (see above) was « normal »: street is going up and down. I stopped ... and then heater started when i went back to the car. Not clear why ... perhaps because the car went back to normal mode for a few seconds. not much effect on the consumption, but these few seconds were enough to raise the heater temp to 26°C.
heater didn’twork again, and that temp went slowly down for the rest of the (short) trip

- SoC went down as expected (no phantom drain), power required went up to 50kW during some accelerations, with negative values when regen/breaking.

the Short trip consumption was still very decent for a cold morning (4°C) at the end: around 21 kWh / 100 km… close to summer values.

I’ll run the same test tomorrow morning, but in Sport plus mode (but driving as usual). Outside temp is expected to be similar

 

[Scandinavian]

- started the car in range mode. drove for about 3km, then stopped to buy croissants () for 7mn, and drove again. see below.

The things you do for scientific consumer information! Well done.

Hope the croissants were nice!

 

[Kaan34]

first test this morning
- car didn’t move for 48hrs, parked outside. Battery temperature was at outside temperature (4°C). both temperatures didn’t change during this short trip (<10km)
- no preheat, no heated seat, no AC, no music, no sport sound, … only headlights needed

- started the car in range mode. drove for about 3km, then stopped to buy croissants () for 7mn, and drove again. see below.

- heater didn’t start, heater fluid stayed at 5°. short trip consumption (see above) was « normal »: street is going up and down. I stopped ... and then heater started when i went back to the car. Not clear why ... perhaps because the car went back to normal mode for a few seconds. not much effect on the consumption, but these few seconds were enough to raise the heater temp to 26°C.
heater didn’twork again, and that temp went slowly down for the rest of the (short) trip

- SoC went down as expected (no phantom drain), power required went up to 50kW during some accelerations, with negative values when regen/breaking.

the Short trip consumption was still very decent for a cold morning (4°C) at the end: around 21 kWh / 100 km… close to summer values.

I’ll run the same test tomorrow morning, but in Sport plus mode (but driving as usual). Outside temp is expected to be similar

This is a really good test I guess, thank you…Consumption is low and seems very stable then..Curious for tomorrow