94Kwh sold, 83KWh used to calculate Kwh/km,... 94Kwh loading?

[Ktof]

Since I barely can drive 300kms with a fully charged battery, I wondered if I really had the 94Kwh battery sold.
So, depleted battery & fully loaded (and yes, looks like 94Kwh), but it also gave me some quite disturbing information:

• When using very low loading speeds (3Kw), I notice all suppliers indicate more power supplied, than consumed (screen or app). Espacially over 85Kw the differences start to be very noticable.
• I notice supplier side going to 94Kwh loaded
• I notice Kwh/km is calculated based on 83Kwh effective

So I wonder (=question):

• confirmation you indeed can 'load'=pay 94Kw (not the effective 83) on a 94Kwh battery?
• where are the missing Kwh? Is the 83kw used to show better consumption rates? Or is the 10Kw missing going into heat dissipation? (In both cases, I think it should be taken into account in the consumption, no )

(and you also confirm you get 250-300-350 kms on mostly highway when your driving style is respectively: autobahn - normal car/porsche driving - driving like a truck, from the derecommended 100% to just nailbiting 3% zone? Temp around 15C outside)

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[kreshi]

Also the charger loses some in the transfer, no? But yeah no EV uses 100% of its battery.

 

[Pozuelo]

I have found that AC charging losses are about 9-10% and DC 800V 270kw is 1-2%. This is the difference between the info of output from charger and input to car, hopefully all to the battery.

 

[tutis]

The net capacity of the 93kwh battery is c. 85 kWh ; that's because fully using the 93kwh to full or completely to empty would rapidly degrade the battery.
Also, welcome to the real world where losses to heat are everywhere.

AC charging losses are around 10%, that's because of the conversion to DC done by the onboard converter. When you DC fast charge, the AC to DC losses are not billed to you; the DC charger measures the DC kWh delivered to you. If you charge on a 800v charger then the losses are usually below 5% (but not zero, as a hot cable will illustrate), and on a 400v charger the losses are closer to 10% again because the onboard inverter steps up the 400v to the 800v the battery needs.

Generally speaking, you get lower losses to heat with lower amps (whether AC or DC). From memory, heat losses increase with the square of amps. So when charging on AC it is usually more efficient to charge at 10-16A then it is to charge at 32A (which is needed for the 22kw AC charging), etc.

 

[Pozuelo]

On further thought, this is logical as you need an AC/DC conversion and a transformer when charging from AC to the Taycan battery. However, when charging at 800V, it just passes through and the loss is only due to resistance from the cables.

 

[Pozuelo]

Ha ha, someone beat me to posting the same thoughts.

 

[AndiL]

Don't forget that the on-board-charger and electronics also consume power that can draw between 500W and 1000W altogether! So you can not assume that all the power that passes the wallbox will land in the battery.

 

[JimBob]

AC charging losses are around 10%, that's because of the conversion to DC done by the onboard converter. When you DC fast charge, the AC to DC losses are not billed to you; the DC charger measures the DC kWh delivered to you. If you charge on a 800v charger then the losses are usually below 5% (but not zero, as a hot cable will illustrate), and on a 400v charger the losses are closer to 10% again because the onboard inverter steps up the 400v to the 800v the battery needs.


[/QUOTE]
Almost. The DC fast charging station still has to convert the AC power from the grid to DC. You are paying for this but it is buried in the price. Given the large number of vehicles and the resulting large power demands, there is a strong push by manufacturers to increase the efficiency of AC-DC conversion through new technology.

 

[W1NGE]

Since I barely can drive 300kms with a fully charged battery, I wondered if I really had the 94Kwh battery sold.
So, depleted battery & fully loaded (and yes, looks like 94Kwh), but it also gave me some quite disturbing information:

• When using very low loading speeds (3Kw), I notice all suppliers indicate more power supplied, than consumed (screen or app). Espacially over 85Kw the differences start to be very noticable.
• I notice supplier side going to 94Kwh loaded
• I notice Kwh/km is calculated based on 83Kwh effective

So I wonder (=question):

• confirmation you indeed can 'load'=pay 94Kw (not the effective 83) on a 94Kwh battery?
• where are the missing Kwh? Is the 83kw used to show better consumption rates? Or is the 10Kw missing going into heat dissipation? (In both cases, I think it should be taken into account in the consumption, no )

(and you also confirm you get 250-300-350 kms on mostly highway when your driving style is respectively: autobahn - normal car/porsche driving - driving like a truck, from the derecommended 100% to just nailbiting 3% zone? Temp around 15C outside)

A proportion of the battery is locked away from use for protection and management - 15% from memory.

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