Main Battery Temperature Query

[QuietLife]

I’m new here and picked up my Macan 4S 10 days ago. I have a question regarding the main battery temperature.

I’ve noticed that my main battery temperature consistently shows 1–2°C above the outside temperature. There is very little movement on the temperature during driving, with maybe a 1 or 2°C increase with some spirited or constant driving at high speed, I also see very little temperature movement if I charge for a couple of hours on my 7kW charger, although I do see a marked increase in temp on DC charging, which is what I'd expect.

Previously, I owned a first-gen Taycan, and I recall the battery temperature increasing to around 10-15°C after AC charging and over 20°C with spirited driving in very cold weather.

I’m curious if other Macan owners are noticing similar behaviour. Afterall battery temperature is crucial for the car to effectively manage the battery, and as we all know, a cold battery is less efficient.

Appreciate any observations and just wanting to allay fears of a faulty temperature sensor or if it’s just typical behaviour on the new PPE platform.

 

[SergeyIndy]

I drove a RWD, 4, and 4S for a day each in different temps and noted the same HV battery behavior that is as you state is different from the Taycan. I know that the battery chemistry is different but not so different that it is efficient at what appears to be way too low of operating temperature.

This is an excellent video about battery temperature among other things:

 

[daveo4EV]

in some cases "conditioning" the battery is less efficient than simply living with the lower efficiency at a given "natural" temperature - dammed if you do, dammed if you don't - the battery is a huge thermal mass - moving it's temp +/- 1C above/below ambient is not cheap in terms of kWh's…

the efficiency drops for "cold" batteries are not that extreme until we're talking below 0C - there are some losses, but they don't become really expensive until the ambient temps get way out of whack vs. LiON ideal temps…

I suggest porsche knows what they are doing - and have programmed the battery thermal management to "do the right thing" across the range of possible battery temps…

lose 3% efficieny to "temperature" or spend 5% to thermally manage the battery to gain back the 3% due to less than ideal temp? As a hypothetical example…I pretty sure the car/battery/thermal-software knows what it's doing…

the car manages the battery - not the owner/driver - leave it alone it knows what it's doing and there is very little you can do to change what it's going to do.

 

[SergeyIndy]

@daveo4EV, this is great context and yes we should trust the battery management to do its thing.

However, I ran into a situation where I did not agree with what battery management was doing during a DC charging session. The good news there are some settings to make it behave differently next time.

 

[QuietLife]

Thanks for the feedback. With driving a Taycan for 3 years and experiencing it's architecture, I presumed I'd see a similar experience with the Macan and battery behaviour. I completely trust the Porsche thermal management system, I have too as I have no other option.

I suppose what surprises me is how the battery thermals are behaving while driving. For instance, on a 160-mile trip, the battery temperature starts at 6°C and only increases to 8°C, despite consistently traveling above the speed limit. Even with traffic, frequent braking regen, and heavy acceleration to regain speed—essentially a cycle of near-constant discharge with occasional regen—it only generates a 2°C increase in heat. By comparison, my Taycan on the same trip and with similar driving behavior would have raised and maintained the battery temperature by at least 15°C within the first 40–50 miles in similar weather conditions.

 

[krissrock]

maybe the battery is designed to maintain a consistent temp, as opposed to a "perfect" temperature?
it may be better for the battery to maintain a temperature more closely to the outside temperature, so that temperature variation is limited with the battery pack heating up and cooling down a lot. So the battery mgmt may not be trying to keep the battery warm, as much as it trying to keep the battery temps stable.

It's about freezing in my region. 32 degrees or below. The car is in the garage, but trips usually start with the battery around 40'ish degrees. But what i've noticed, is that battery stays exactly around that temp. It doesn't drop down closer to 32, nor does it right more than a degree or two after driving a while...

 

[SergeyIndy]

The battery generates heat during discharge or recharge via regen, as one of the recommendations for the cold weather to warm up the battery quicker for DC charging is to use the yo-yo effect. I do not have Macan EV but the next time I get one for a drive, I will try to see if yo-yo will move the temp higher, just for curiosity. Yo-Yo mode is to accelerate fast and then slow down fast to get as much discharge and recharge via regen as possible, typically used if there is not enough time to preheat the battery by normal driving before arriving at a DC charger.

 

[byebye]

My guess is that the front electrical flaps stay open, even if it’s freezing. Why, I don’t know, as, like you, I think it’s more appropriate under cold weather to not cooling battery with new fresh air…
Only a guess because I can’t monitor these electrical flaps while driving

 

[QuietLife]

I was thinking something similar that the front flaps staying open and not closing correctly, the cars actually back at Porsche at the moment as it went over to a local car detail specialist to have a Ceramic coat put on it as they couldn't do it over the Christmas period. It also has a suck RPC+ software install in notifications and the drivers door is quite difficult to close without a good slam, so they are double checking everything including the cooling side to ensure it's all working correctly.

Can't complain, they've been very good and even loaned me a 911 cab for a few days, pity it's not the summer and the UK weather been cold otherwise I would have had a few days off work to just drive the 911 around...

Sponsored