Preconditioning battery temp for DCFC

[Hirschaj]

I've seen a few posts about battery temperatures when fast charging. I'm on a mini road trip and decided to pay careful attention to my car this morning as it routed me to an EA station. When I added the route into the PCM my battery was at 73F. By the time I got to the charging station (25 minutes later) my battery was 103F. I charged for 20 minutes and at the end of the charging session my battery was at 105F. This is in Texas in about 70-80F air temperature (probably closer to 70 at the start of the route and closer to 80 by the end of charging).

My max charge rate was about 143kW but I started with 51% charge. The charge rate tapered to about 93kW by the end of the charging session at 81% SoC.

What are other folks seeing for temps and charge rates?

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[Scandinavian]

Absolutely normal figures both for temperature and charge rate.

If you look at the Out is Spec video recently published you will see very similar temp figures. And the charge curve is similar to some published by Fastned some year(s) ago.

 

[bsclywilly]

I’ll see between 103-109F preconditioning temp when I have selected a charging destination in the nav and have at least 20-30 min to get there. Charging rate I find depends more on the charger and whether it is working properly or not. When it is, 240-260kW from single digit SOC up to around mid 55%. Battery temp at end of session depends highly on charge rate and ambient so results vary greatly.

I should note that the preconditioning works whether the charge planner is selected or not. I always have the charge planner deselected (since it’s mostly useless).

 

[Scandinavian]

I should note that the preconditioning works whether the charge planner is selected or not. I always have the charge planner deselected (since it’s mostly useless).

When you say you have the charge planner deactivated, do you then mean the Porsche Intelligent Range Manager (PIRM)? (Not particularly intelligent in my experience though).

Because you say in the beginning that you properly add a charger in the nav system in order to preheat?

 

[bsclywilly]

When you say you have the charge planner deactivated, do you then mean the Porsche Intelligent Range Manager (PIRM)? (Not particularly intelligent in my experience though).

No, the regular charge manager is disabled. I don't have the PIRM option.

 

[simcity]

Absolutely normal figures both for temperature and charge rate.

If you look at the Out is Spec video recently published you will see very similar temp figures. And the charge curve is similar to some published by Fastned some year(s) ago.

Wonder if the Fastned curves need a refresh post the big uPdate and MY23?

 

[simcity]

Was wondring whether I should bother enabling "battery-saving fast charging" to cap the DCFC rate to 200 kW, but if the curves above are still accurate, then its only pulling ≥ 200 kW in the first 25%-ish of SoC anyway. Seems a bit moot, if I pull in with say 30% SoC

 

[Scandinavian]

Wonder if the Fastned curves need a refresh post the big uPdate and MY23?

I have a feeling these graphs need an update. I have not found any fresher ones for the Taycan though. Seems the car does not throttle down as early as shown.

 

[Scandinavian]

This one was done in 2021 and already at this time the charging curve was different to the Fastned one. This is very close to what I have experienced at several Ionity stations. And in such case the battery saving setting would make a difference. Slightly longer charging times then but quite marginal. Perhaps a few minutes if you charge from 10 to 80%

 

[Jayyvr890]

I discovered battery temp condition will vary a lot depending on your overall route and charge time so impossible to compare even with the same car.

If you have a short charge session followed by a long drive after (as programed into PCM) the battery temp will rise very high nearing redline presumably as the car knows you have a long drive coming up where the battery can be cooled gradually.

If there is only a short drive after the charge, battery cooling will be a lot more aggressive while charging keeping the battery temp much more in range.

Also I noticed that the cooling fans spin a lot faster if you get out of the car and lock it as opposed to sitting in the car listening to music etc... PCM probably diverting AC power for battery cooling. I now make a habit of leaving the car and just monitor the charge speed on my phone instead.

 

[Scandinavian]

I discovered battery temp condition will vary a lot depending on your overall route and charge time so impossible to compare even with the same car.

If you have a short charge session followed by a long drive after (as programed into PCM) the battery temp will rise very high nearing redline presumably as the car knows you have a long drive coming up where the battery can be cooled gradually.

If there is only a short drive after the charge, battery cooling will be a lot more aggressive while charging keeping the battery temp much more in range.

Also I noticed that the cooling fans spin a lot faster if you get out of the car and lock it as opposed to sitting in the car listening to music etc... PCM probably diverting AC power for battery cooling. I now make a habit of leaving the car and just monitor the charge speed on my phone instead.

Good point about closing the car. I normally just set the car in Sport Plus while charging and then the fans go crazy. And a lot of hot air is pushed out from the front wheels.

 

[McgR]

I think they did. Saw this today.

I saw that Fastned now also shows as a charging location in My Porsche app and that it should be accessible with charge service for 35 cent per kWh and 35 cent per minute. Didn’t try it yet but until now I always used plug and charge. This works well but at a much higher Fastned rate than with Porsche.This would be good news.

 

[mystermykee]

I discovered battery temp condition will vary a lot depending on your overall route and charge time so impossible to compare even with the same car.

If you have a short charge session followed by a long drive after (as programed into PCM) the battery temp will rise very high nearing redline presumably as the car knows you have a long drive coming up where the battery can be cooled gradually.

If there is only a short drive after the charge, battery cooling will be a lot more aggressive while charging keeping the battery temp much more in range.

Also I noticed that the cooling fans spin a lot faster if you get out of the car and lock it as opposed to sitting in the car listening to music etc... PCM probably diverting AC power for battery cooling. I now make a habit of leaving the car and just monitor the charge speed on my phone instead.

What if your route was only to the charger? But thanks, I'll keep that in mind whenever I need a DC charge-- power off and get out of the car.

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