Preheat setting in the My Porsche app

[f1eng]

There has been some discussion about how to warm up the battery for range/performance reasons.

The timer function in the PCM includes both getting to the required charge and pre-heating the battery to a pre-set time just in time to use the car, which is excellent if you use the car at the same time every day.

I guessed that because the pre-heat timer in the app is for one hour it must be warming the battery as well as the cabin since the cabin air is warm in minutes so I decided to test it.

Yesterday I checked, rather than preheating for 10 minutes to warm up the cabin I did so for 40 minutes and checked the before and after battery temperature.

It increased from 9C to 16C during these 40 minutes showing the preheat function heats both cabin and battery, though the battery obviously takes far longer being hunrdeds of kg of material rather than a few kg of leather and air.

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[Dabz]

That's excellent info, thanks - I wondered why it would default to an hour when the cabin can heat up in minutes. I wonder if the extra efficiency gained from a warmer battery offsets the extra power used to heat them...and what the minimum journey needed to "break even" would be. My commute is just 2 miles so I suspect pre-heating for 10 mins and forgoing extra efficiency is better than wasting an hour on warming all the battery pack.

 

[f1eng]

That's excellent info, thanks - I wondered why it would default to an hour when the cabin can heat up in minutes. I wonder if the extra efficiency gained from a warmer battery offsets the extra power used to heat them...and what the minimum journey needed to "break even" would be. My commute is just 2 miles so I suspect pre-heating for 10 mins and forgoing extra efficiency is better than wasting an hour on warming all the battery pack.

I think having such a big cold battery is going to be inefficient for the forst 10 miles or so whether by letting the car system heat the battery as you go or from the mains before leaving

I didn’t make any attempt to evaluate how much power was used during the preheat, the car was plugged in.

 

[Vercingetorix]

Wonder how much just charging alone raises the temperature of the battery.

 

[f1eng]

Wonder how much just charging alone raises the temperature of the battery.

Test it on your car to find out.

 

[Vercingetorix]

Test it on your car to find out.

I charge with 110 Volts. Wouldn’t be of much use.

 

[rim23]

Wonder how much just charging alone raises the temperature of the battery.

I charge at 10A at 220V. It raises for about 10-12C

 

[f1eng]

I charge with 110 Volts. Wouldn’t be of much use.

OK I am in the process of checking using my standard single phase wall box which is supplying 7.2 kW to the car (which is charging at 6.7kW confirming the 500 watt overhead I always see). Pre-heat is off.

After 40 minutes the battery temperature had increased from 10C to 11C.

I will add more temperature info a bit later.

 

[f1eng]

After a further 50 minutes the temperature was 14C, so in 1 ½ hours went from 11 to 14 with just charging current.

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