Battery Cooling

[Kakatus10]

I live in a hot climate (Arizona), and was wondering when the battery cooling is engaged.

I have read in the user manual to drive in Normal mode to keep the front air vents open to optimize cooling after a DCFC session, I suspect normal mode in general cools the battery better than Range mode, so I will be avoiding Range mode unless absolutely needed.

Does activating the onboard AC system also cool the battery's? I have heard the systems are somewhat linked, not sure how, it'd be interesting to be able to schedule the pre-cool function mid-day to drop the temperature of the pack.

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[XLR82XS]

This may help:
https://newsroom.porsche.com/en_US/products/taycan/battery-18557.html

 

[Kakatus10]

Thanks, as per the article:

"Depending on the outside temperature, the battery is preconditioned to a certain temperature level when the vehicle is connected to the mains for charging. The interior can be preconditioned independently of the mains."

It would seem interior cooling is separate from the 'mains' which appears to be what the battery relies on for thermal management.

 

[NC_Taycan]

There is a single compressor (heat pump) for the interior and battery cooling and heating. Valves control what is used where. It is not necessary to activate the interior cooling to cool the battery if cooling is needed. That said, the optimal temperature for the battery is up there (though so are the temperatures out West). Unless your battery temp is above 120 deg. F, don't expect the car to engage cooling. You won't start to see thermal throttling until the battery temperature is even higher. I didn't get hot enough on a track day but I believe @daveo4EV has. I think my point in all of this is not to worry about it - don't second guess the car and simply enjoy the drive.

 

[daveo4EV]

I have experienced reduced power on track when the battery temperature was at 132-F - 131 I had full power - 132-F power reduced…when the car was taken off track the battery temp quickly dropped into the low 120’s - and letting the car sit idle hte battery temp was back below 100-F in less than 20 minutes, and across the course of an hour dropped back to the low 80’s…

on track driving at 1/3 to 1/2 pace allowed the battery to cool and drop below the 132-F mark and restore “full power” - but only briefly as returning to full pace it quickly rose again to 132-F and again reduced power…

unless driving “flat-out” it’s unlikely the battery will reach that temperature under normal driving conditions.

even with reduced power however the Taycan was mostly good for driving - with only “full power” being reduced - for normal driving I don’t think you would notice the reduced power at this battery temperature.

 

[daveo4EV]

I live in a hot climate (Arizona), and was wondering when the battery cooling is engaged.

I have read in the user manual to drive in Normal mode to keep the front air vents open to optimize cooling after a DCFC session, I suspect normal mode in general cools the battery better than Range mode, so I will be avoiding Range mode unless absolutely needed.

Does activating the onboard AC system also cool the battery's? I have heard the systems are somewhat linked, not sure how, it'd be interesting to be able to schedule the pre-cool function mid-day to drop the temperature of the pack.

the pack will be cooled/heated as necessary by the vehicle - LiON batteries have a temperature operating range - the car will automatically manage the pack temperature at all times - even while the car is idle, charging, or being driven - there is no need to manage anything. The biggest threats to heat up the pack are DCFast charging, and flat-out driving for more than 15 minutes - otherwise pack temperature is rarely more than 20F above ambient - 132F seems to be the point where Porsche will ‘throttle’ maximum discharge rates (reduce throttle power) and I’m going to assume it is also when Porsche will engage maximum cooling for the pack.

the car should take care of itself and there is no need to engage any manual thermal management.

 

[Kakatus10]

There is a single compressor (heat pump) for the interior and battery cooling and heating. Valves control what is used where. It is not necessary to activate the interior cooling to cool the battery if cooling is needed. That said, the optimal temperature for the battery is up there (though so are the temperatures out West). Unless your battery temp is above 120 deg. F, don't expect the car to engage cooling. You won't start to see thermal throttling until the battery temperature is even higher. I didn't get hot enough on a track day but I believe @daveo4EV has. I think my point in all of this is not to worry about it - don't second guess the car and simply enjoy the drive.

I am mostly concerned with longevity of that pack. As you've stated only going 9/10ths or above will get the battery out of line, the powertrain never overheats to my knowledge, it's 270KW regen braking, so you have to be digging hard into the brakes frequently to overheat the pack. This is shown based on the results of Japanese EV racing circuits.

 

[Kakatus10]

otherwise pack temperature is rarely more than 20F above ambient

I am mostly concerned with ambient temperatures actually, as you can see scrolled 60% down the page "Vehicles driven in hot temperatures show faster decline in battery SOH" https://www.geotab.com/blog/ev-battery-health/

 

[daveo4EV]

I am mostly concerned with ambient temperatures actually, as you can see scrolled 60% down the page "Vehicles driven in hot temperatures show faster decline in battery SOH" https://www.geotab.com/blog/ev-battery-health/

I"m not sure there is any data to support that for LiON battery packs that are temperature managed - it is certainly true for non-temperature managed batteries like the Leaf - however higher ambient temperatures don't matter if the battery is actively managed like Tesla's, Bolts, Taycan's, eTrons etc…

conversations with LiON battery engineers at a major tech company I used to work for that ships millions of battery based devices indicate the major issue is charging/discharging a LiON battery "outside" it's temperature range - just sitting there with no charge/discharge activity has very little impact on the battery - and while the vehicle is "on" and charging/discharging it's actively managing the batteries temperature to keep it in the "zone"…any impact to overall battery life is likely to be fractional vs. normal aging - normal aging of LiON EV batteries show 10-16% loss of capacity after 8-12 years…

in general worrying about the battery is futile since there is NOTHING you as a consumer can do about it - the battery system is 100% managed by the vehcile's software so there is virtually nothing you can do to influence it's overall capacity at the end of it's life…

the ONLY data we have showing extreme battery degrading is from a fleet of Tesla Taxi's that were DCFast-charged/Supercharged EVERY DAY EXCLUSIVELY - sometimes MULTIPLE TIMES A DAY - and after 4 years they had lost 30% capacity and the batteries were replaced to recapture the lost range - but that's on vehicles being fast charged multiple times a day 360 days a year - and even with the battery replacement cost the vehicle's overall cost per mile driven was less than gas cars for similar milage…

8 year/unlimited mile warranty - nothing you can do to influence the battery (there is too much software between you and the battery) - just charge and drive the car and enjoy. Unless you are fast charging multiple times a day every day there is very little you can do or will do the the battery simply driving the vehicle around even in higher ambient temperatures.

 

[daveo4EV]

https://rennlist.com/forums/taycan/1184811-cost-to-replace-taycan-s-battery.html

 

[daveo4EV]

this post from about 2 years ago has also been well received…

https://rennlist.com/forums/taycan/1125698-battery-replacement-cost.html#post15593983

 

[buruburu]

I just had a long long roadtrip where we were driving for more than 10 hours a day thru Utah / Kansas / Idaho / Colorado / Texas / Oklahoma where ambient temperatures were in the mid 90s and somtimes in the high 90s and even in the low 100's. Car was in range mode and the car kept the battery at a steady 91-2 degrees the entire way.

As noted by others, DC fast charging will get the battery up to about 113-4 degrees, but after would come back down again even after driving in range mode after about 20-30 minutes.

I have my gauges set up on my Taycan to display battery temperature since I'm in the NW where ambient is cooler and seeing the temperatures lets me know if I'm going to be getting optimal charging speeds up here.

 

[Kakatus10]

I"m not sure there is any data to support that for LiON battery packs that are temperature managed - it is certainly true for non-temperature managed batteries like the Leaf - however higher ambient temperatures don't matter if the battery is actively managed like Tesla's, Bolts, Taycan's, eTrons etc…

conversations with LiON battery engineers at a major tech company I used to work for that ships millions of battery based devices indicate the major issue is charging/discharging a LiON battery "outside" it's temperature range - just sitting there with no charge/discharge activity has very little impact on the battery - and while the vehicle is "on" and charging/discharging it's actively managing the batteries temperature to keep it in the "zone"…any impact to overall battery life is likely to be fractional vs. normal aging - normal aging of LiON EV batteries show 10-16% loss of capacity after 8-12 years…

in general worrying about the battery is futile since there is NOTHING you as a consumer can do about it - the battery system is 100% managed by the vehcile's software so there is virtually nothing you can do to influence it's overall capacity at the end of it's life…

the ONLY data we have showing extreme battery degrading is from a fleet of Tesla Taxi's that were DCFast-charged/Supercharged EVERY DAY EXCLUSIVELY - sometimes MULTIPLE TIMES A DAY - and after 4 years they had lost 30% capacity and the batteries were replaced to recapture the lost range - but that's on vehicles being fast charged multiple times a day 360 days a year - and even with the battery replacement cost the vehicle's overall cost per mile driven was less than gas cars for similar milage…

8 year/unlimited mile warranty - nothing you can do to influence the battery (there is too much software between you and the battery) - just charge and drive the car and enjoy. Unless you are fast charging multiple times a day every day there is very little you can do or will do the the battery simply driving the vehicle around even in higher ambient temperatures.

I appreciate it, you alleviated a lot of my concerns!

 

[benver]

...
in general worrying about the battery is futile since there is NOTHING you as a consumer can do about it...

Pardon me to disagree. Charging to a max of 85% will help keep the battery in better shape compared to a full 100% charge every time.
Also minimize the use of fast DC charging and don't go below 10%.

 

[kort]

Pardon me to disagree. Charging to a max of 85% will help keep the battery in better shape compared to a full 100% charge every time.
Also minimize the use of fast DC charging and don't go below 10%.

not quite right.
charging to 100% or going below 10% SOC isn't ideal but as long as the car is driven immediately to draw down the SOC or the car is charged ASAP in order to bring up the SOC there really isn't a problem going to those levels.

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