PMCC - Overheated

[Bsteffes]

So I finally got a chance to really test the PMCC last night. Car was @ 19% and set to stop at 85%. Plugged it in around 4:45pm and immediately saw the car go to about 9.3kW charging. Checked on the car around 8pm....and noticed it had dropped to 2.1kW. Thought this was odd....but maybe its part of the "optimization" setting since I don't care when it its done. Went into garage around 10pm and noticed the PMCC had a red screen saying it was too hot / limited service. See attached pic. The charger, the enclosure (dock) and the wire to the car.....were HOT. didn't take temps...but almost too hot for me to touch for longer than couple of seconds.

I know my electrical is good. Was installed with correct wire gauge, bends, junction, and circuit. The circuit itself was warm...but not hot and nothing out of the ordinary. But the PMCC...ws cooking itself. Garage was 90 degrees (thanks FL)....but one would think Porsche would have taken this into consideration. I have fully charged the car with a 3rd party unit (Mustart) and it had ZERO issues. Warm...but nothing out of the ordinary. Pulled a steady 38.9 amps from plug...and delivered 9.1kW to car without issues.

Anyone else seen this?

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[daveo4EV]

hmmm -I’ve not seen this - but I‘m sorry to say I’m not surprised - I believe the PMCC is not the highest quality EVSE on the market - it is certainly the most expensive by quite a margin.

It seems once again to be perfectly safe - but not useful to the average consumer.

I’m increasingly convinced there are better non-Porsche EVSE solutions one should pursue.

I’m particuarly amused by the recommendation to “avoid direct sunlight” on a “mobile charger“ - cause ya’know when I’m using it as a mobile charger I can control that sort of thing.

 

[HelfFL]

So I finally got a chance to really test the PMCC last night. Car was @ 19% and set to stop at 85%. Plugged it in around 4:45pm and immediately saw the car go to about 9.3kW charging. Checked on the car around 8pm....and noticed it had dropped to 2.1kW. Thought this was odd....but maybe its part of the "optimization" setting since I don't care when it its done. Went into garage around 10pm and noticed the PMCC had a red screen saying it was too hot / limited service. See attached pic. The charger, the enclosure (dock) and the wire to the car.....were HOT. didn't take temps...but almost too hot for me to touch for longer than couple of seconds.

I know my electrical is good. Was installed with correct wire gauge, bends, junction, and circuit. The circuit itself was warm...but not hot and nothing out of the ordinary. But the PMCC...ws cooking itself. Garage was 90 degrees (thanks FL)....but one would think Porsche would have taken this into consideration. I have fully charged the car with a 3rd party unit (Mustart) and it had ZERO issues. Warm...but nothing out of the ordinary. Pulled a steady 38.9 amps from plug...and delivered 9.1kW to car without issues.

Anyone else seen this?

Yes, unfortunately I have seen that message a few times. I'm in Florida too. Usually, you just have to unplug, wait for everything to cool down and then try again. Not very comforting though.

I presume you have seen the other threads regarding the temperature issues relating to the PMCC. Coincidentally, I went to charge last night for the first time time in a few days and upon plugging in the charger to my car, I got the following:

I unplugged the car, waited a few minutes and then plugged in again. Message went away and charging was fine. I am, however, based on Porsche's latest recommendation, charging at 32 amps instead of the full 40 amps to try to help limit the heat load on the charger and my circuit breaker.

 

[daveo4EV]

I can also speculate that we all are not doing ourselves any favors by running these devices inside the enclosed cabinets (Porsche Docks) with limited/zero airflow

the combination of 40 amps, no airflow, enclosure with limited air circulation, and 90F ambient conditions it probably highlights Porsche’s borderline choices with regards to the PMCC.

it’s good to see the device regulated itself and limited the charging current (again very safe design) but disappointing that this device has these issues.

there are better choices for an EVSE with more robust characteristics for way way less money.

 

[rquinton]

Yes, unfortunately I have seen that message a few times. I'm in Florida too. Usually, you just have to unplug, wait for everything to cool down and then try again. Not very comforting though.

I presume you have seen the other threads regarding the temperature issues relating to the PMCC. Coincidentally, I went to charge last night for the first time time in a few days and upon plugging in the charger to my car, I got the following:

I unplugged the car, waited a few minutes and then plugged in again. Message went away and charging was fine. I am, however, based on Porsche's latest recommendation, charging at 32 amps instead of the full 40 amps to try to help limit the heat load on the charger and my circuit breaker.

I just found this on the NHTSA site and was wondering if this would help with the overheating charger cable. Thoughts? Looks like it might be an in service update.


https://static.nhtsa.gov/odi/tsbs/2020/MC-10179210-0001.pdf

 

[HelfFL]

I can also speculate that we all are not doing ourselves any favors by running these devices inside the enclosed cabinets (Porsche Docks) with limited/zero airflow

the combination of 40 amps, no airflow, enclosure with limited air circulation, and 90F ambient conditions it probably highlights Porsche’s borderline choices with regards to the PMCC.

it’s good to see the device regulated itself and limited the charging current (again very safe design) but disappointing that this device has these issues.

there are better choices for an EVSE with more robust characteristics for way way less money.

Yes, to your point @daveo4EV, whenever I charge I keep the dock door and even my electrical panel door open while charging.

 

[daveo4EV]

I can recommend the following ClipperCreek products which are extremelly safe, robust, reliable, but not mobile.

https://store.clippercreek.com/level2/level2-40-to-80/HCS-50P-Plug-in-40 Amp-EVSE-Charging-Station-25-ft-over-molded-cable-NEMA-14-50

they also make a 50 amp hardwired or 6-50P version - so swapping one of these in for your PMCC would be almost plug & play.

if you wiring and subpanel can handle the HCS60 (48 amp charging) will also work and charge the Taycan faster than the HCS50 or PMCC.

https://store.clippercreek.com/level2/level2-40-to-80/hcs-60-48-amp-ev-charging-station

Neither of these two recomendatons are “mobile” chargers. Install one of these for home use, and then you can limit your PMCC usage to only mobile usage when you’re on the road, although there are also better choices for a “mobile” EVSE vs. the Porsche option.

 

[daveo4EV]

I’m also wondering about the heat management of the vehicle and it’s proximity to the PMCC itself. I’ve notice a super quiet slightly warm flow of air coming from the driver’s side front wheel well during the 40 amp charging process - this air flow is not super heated, but is warmer than ambient - if your PMCC unit was particularly close to this warm airflow it’s not going to help the PMCC’s heat management…I have noted that for 2+ hour charging sessions I can raise the temperature of my entire garage by 1F to 3F - which given the volume of a two car garage is actually quite a bit of thermal energy in the grand scheme of things.

is the PMCC unit itself close to the driver’s side front wheel well? Do you also notice this warm airflow during charging?

 

[Bsteffes]

hmmm -I’ve not seen this - but I‘m sorry to say I’m not surprised - I believe the PMCC is not the highest quality EVSE on the market - it is certainly the most expensive by quite a margin.

It seems once again to be perfectly safe - but not useful to the average consumer.

I’m increasingly convinced there are better non-Porsche EVSE solutions one should pursue.

I’m particuarly amused by the recommendation to “avoid direct sunlight” on a “mobile charger“ - cause ya’know when I’m using it as a mobile charger I can control that sort of thing.

Agree 100% with both your comments and HellFL.
but makes the $1200 charger mandatory. I then willingly spent $470 for the beautiful dock. One would think Porsche engineers account for an enclosed charger. In a hot garage.
So $1700 later...I have to reduce my charging time???
I still think it’s starts with using a 16amp rated cord with a 50 amp service pulling 40Amps continuous.
just happy that it protects itself. That is the only “plus”.
my breaker and wiring are well within what I would call normal.no different than a laptop power brick warmth.
Porsche missed the mark for sure. Now one can only hope they step up and fix it.

 

[Bsteffes]

I’m also wondering about the heat management of the vehicle and it’s proximity to the PMCC itself. I’ve notice a super quiet slightly warm flow of air coming from the driver’s side front wheel well during the 40 amp charging process - this air flow is not super heated, but is warmer than ambient - if your PMCC unit was particularly close to this warm airflow it’s not going to help the PMCC’s heat management…I have noted that for 2+ hour charging sessions I can raise the temperature of my entire garage by 1F to 3F - which given the volume of a two car garage is actually quite a bit of thermal energy in the grand scheme of things.

is the PMCC unit itself close to the driver’s side front wheel well? Do you also notice this warm airflow during charging?

So I notice heat from both sides. And yes it’s significant. Lifelong Floridian. Hot garages are common. But this thing is clearly adding heat. You are correct. A two car garage going up in temps by 3 degrees is huge. Which is fine in the grand scheme of things. A charger shutting down...bad.
My charger is located on the passenger side.

 

[daveo4EV]

hmmm -I"ve not noticed/checked/paid-attention-to any soft quiet heated airflow from the passenger side - I"ll have to check it out - but your PMCC does seem perfectly positioned such that the exact area the airflow is exhausting will add additional warmth to the general area of the PMCC Dock - we'd need a thermal engineer (which I'm not) to be able to determine if it's significant enough to make a difference - I can probably say it's not helping…

when I install EV chargers I always install them as close the garage door as possible so that the charging cord has maximum reach into the driveway…this tends to position them towards the back of the vehicle rather than the mid-section…

as to if that makes a consequential difference I really can't say with out a more detailed study and some expertise in thermals which I sorely lack.

in any case I believe we're gaining a better picture of the PMCC and it's relative reliability and robustness…

it appears 100% safe, but perhaps not the best, most reliable or robust EVSE on the market. It is certainly the most expensive and complex one on the market.

I only use my PMCC occasionally - and generally have been charging my Taycan using my existing multi-EVSE shared circuit Tesla Wall Chargers - I get the 48 amp charge rate and the load sharing for charging the Taycan, Model X, and Bolt all at the same time.

 

[daveo4EV]

@Bsteffes next time you charge - you should try leaving the Porsche Dock door - open and getting some actual temps would be illuminating.

getting some data from your charging session with door open/close - and ambient temperature would probably help with any escalation you might consider with Porsche if you want them to care about this issue.

 

[Vim Schrotnock]

That is truly ridiculous if Porsche has designed a very expensive charging box to hold their charger and it overheats when the garage temperature exceeds 90°. That is an absolute recall and replacement situation in my opinion.

 

[Bsteffes]

That is truly ridiculous if Porsche has designed a very expensive charging box to hold their charger and it overheats when the garage temperature exceeds 90°. That is an absolute recall and replacement situation in my opinion.

Will do that. Need to wait until I need more charge. At least 4 hours worth..which should be 30-40%.
I will take some temp readings and send them.
thanks again!

 

[r553]

I have limited my charging current to 30 amps in honor of the 10 gauge input pigtail. I'm in FL too but my car is outdoors when charging at night. I also got my first post Taycan electric bill: +$40.

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