Battery Temp

[Dolomite]

I was having issues with getting any kind of fast charge into the vehicle and started doing some reading about battery temperature. Battery was at 16% SOC when I started.

Found it interesting that at a 350 kW charging station if the battery temperature was 31° or lower the maximum active power it would put in the car was 40 kW. The ambient air temperature was quite high at 26° with a lot of humidity here in Toronto at the time.

I disconnected the car, programmed the the navigation to take me to a station 20km away and drove around for 5mins in sport plus and the battery temperature went up to 34° quite quickly and I came back and was instantly able to get this level of charge once I plugged back in.

I am aware that battery temperature obviously effects rate of charge but surprised that on a hot day with only 2° difference battery temp I was able to get rapid charging and dead slow when at 31°
It did start to throttle down as SOC increased but I still was able to maintain a pretty good rate of 179kw at 63% SOC, battery temp rose to 51° very fast during rapid charging.

 

[kort]

it is possible that the charger you were at was not working properly

 

[Dolomite]

it is possible that the charger you were at was not working properly

I returned to the exact same charger after the 5 minute drive.

 

[f1eng]

It is not by chance there is a battery conditioning function to get the battery up to an optimum temperature before fast charging.
The optimum temperature range isn't that wide either, it slows if too hot as well.

 

[Dolomite]

It is not by chance there is a battery conditioning function to get the battery up to an optimum temperature before fast charging.
The optimum temperature range isn't that wide either, it slows if too hot as well.

So I guess if one wants to take advantage of the fast charge option you pretty much have to use the navigation and plug in and use that to condition the battery to take advantage of the charge rate.

Do you think the navigation and the precondition program is sophisticated enough to decipher whether you are heading to a fast charging station or just a regular one.

I’m wondering if it only preconditions the battery if you’re heading to a fast DC charge one?

 

[f1eng]

So I guess if one wants to take advantage of the fast charge option you pretty much have to use the navigation and plug in and use that to condition the battery to take advantage of the charge rate.

I haven't got mine yet so I haven't checked to see if it can be done manually.

 

[kort]

So I guess if one wants to take advantage of the fast charge option you pretty much have to use the navigation and plug in and use that to condition the battery to take advantage of the charge rate.

you could also put the car into sport plus mode when 10 miles away from the charger, drive it a bit hard and that should get the temp up

 

[NC_Taycan]

I’m wondering if it only preconditions the battery if you’re heading to a fast DC charge one?

Yes, and only if the Porsche navigation system already knows it's a fast charger. If you just plug in the address, that's not good enough.

Also note if your predicted SOC at arrival is 0%, the battery may not pre-condition, instead saving precious energy for the traction motor. Let's not discuss why I know this.

 

[chrisk]

I can easily get 100Kw charge rate with SoC ~50% and battery temperature ~30 C. I am not sure why you were only getting 40KW.

Btw 51 C is pretty close to turtle mode. I have never seen my battery so hot.

 

[NC_Taycan]

Definitely don't discount the impact of the grid - even if there are no other cars charging, just turning on 150 kW or even 270 kW of load is a big step function. I don't know how it works, but I expect there is some sort of communication with the grid supplier to confirm the load can be supplied. Maybe there is a reply back with the max that is available at the time and the station reacts accordingly.

 

[feye]

Battery was at 16% SOC when I started.

And the second time? Apparently, really fast charging only works with lower SoC? Maybe made a difference?

 

[Dolomite]

Yes, and only if the Porsche navigation system already knows it's a fast charger. If you just plug in the address, that's not good enough.

Also note if your predicted SOC at arrival is 0%, the battery may not pre-condition, instead saving precious energy for the traction motor. Let's not discuss why I know this.

there Are

And the second time? Apparently, really fast charging only works with lower SoC? Maybe made a difference?

The SOC on the first session was maybe 20% max.

 

[Jhenson29]

Definitely don't discount the impact of the grid - even if there are no other cars charging, just turning on 150 kW or even 270 kW of load is a big step function. I don't know how it works, but I expect there is some sort of communication with the grid supplier to confirm the load can be supplied. Maybe there is a reply back with the max that is available at the time and the station reacts accordingly.

I’m not an expert in power distribution systems, but I don’t think that sounds especially large. If that load is a problem, then it sounds like it’s not sized properly. Unless I’m missing something.

I regularly see 150 HP motors on across the line starters. And 400 HP on soft starters. There’s ramping on the soft starters, but we usually get to full volts in 3 sec at 350% current.

Some of the larger machines I’ve worked on were approaching 10MW, 5MW of which would come on over a period of two seconds. And that was just one of many machines in one plant.

But, counter point to my point, the engineer who sized the feed on that particular system didn’t know the system was expected to run at 100% continuously for those 5MW, so the first time we ran it, the voltage dropped so low things started just shutting off. We had to run at 75% capacity until a larger feed and additional transformer could be added for the full power.

So, I’m not saying things can’t be undersized (they can), but 270kW doesn’t sound like a lot to me.
. . .
That’s what the Taycan needs. 5MW charging. I bet that costs extra.

 

[feye]

The SOC on the first session was maybe 20% max.

That could have been just the difference. I read people complaining, that the super fast charging only works with starting charging at low SoC. They said it looks like Porsche is trying to keep the marketing promise of 5-80% SoC in less than 23 min...

 

[Fish Fingers]

Not sure where I got this from.....but maybe useful here.

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