Power loss when charging

[MrJohnDolk]

Hi all,

Today I almost ran out of juice, and for the first time had to charge more than just 20 kWh..

I plugged in with 4% SoC, and charged 60Kwh, and the car told me 67% SoC was achieved..

if this 63% increase equals 60 kWh, and my available battery capacity is supposed to be 83,4 kWh, then it seems that I have to spend more than 95kwh to fill the battery to 100%....

is it normal that as much as 12 kWh is lost in ”the cables”? I find that very much indeed...

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[Doc B]

Hi all,

Today I almost ran out of juice, and for the first time had to charge more than just 20 kWh..

I plugged in with 4% SoC, and charged 60Kwh, and the car told me 67% SoC was achieved..

if this 63% increase equals 60 kWh, and my available battery capacity is supposed to be 83,4 kWh, then it seems that I have to spend more than 95kwh to fill the battery to 100%....

is it normal that as much as 12 kWh is lost in ”the cables”? I find that very much indeed...

I think you can expect 10-15% loss. If you look at the Taycan charging rate on the PCM screen, it is usually (at least for me) at least 10% less than the charging rate on the charger (I use a Zappi). Porsche never seem to tell you that when they estimate charging times - my 7kWh charger takes around 14-15 hours to fully charge the Taycan, rather than the 12-13 hours that is sometimes advertised.

 

[daveo4EV]

some power will also be used to condition the battery (keeping it at correct temperature) - so between charging losses (5-10%) and running HVAC to keep battery in correct temperature range you will use more power than tecnically needed to just charge the battery.

 

[MrJohnDolk]

some power will also be used to condition the battery (keeping it at correct temperature) - so between charging losses (5-10%) and running HVAC to keep battery in correct temperature range you will use more power than tecnically needed to just charge the battery.

that sounds reasonable, my car is in a heated garage (20 degrees Celsius), and battery temp is 30 degrees - does it draw power to cool the battery pack and keep it at 30?

 

[daveo4EV]

it will both heat/cool the battery (as necessary) to keep optimal temperature for the battery - it’s a longevity thing. if the battery is too cold it will heat it, and if the batter is too warm it will cool it.

Porsche’s on board battery management software will use power as necessary to maintain the battery.

 

[feye]

if this 63% increase equals 60 kWh, and my available battery capacity is supposed to be 83,4 kWh, then it seems that I have to spend more than 95kwh to fill the battery to 100%....

is it normal that as much as 12 kWh is lost in ”the cables”? I find that very much indeed...

Charging from 0% to 100% SoC. Average temperature 32°C. About 15% charging loss.

I think this could be quite a bit higher if you charge the car in really cold condition. But I cannot test this. It is also hard to calculate, because the net capacity of the battery is not really exactly 83.7kWh.

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