Using a campground plug

[daveo4EV]

the PMC+/PMCC are not very good EVSE’s for the North American market - they are expensive, physically large, heavy, temperamental, and the 10-gauge wire porsche ships for the 50/40 amp plugs is only barely safe and gets quite hot during normal usage (8 gauge wire would’ve been a better choice)

Porsche’s in car software for charging is:

• is too complex for normal humans to figure out
• not very robust in the face of changing amperage from the J-1772 specification

Porsche’s charging software also suffers a fatal flow for charge scheduling - since the German seems desparate to have the car finish “just in time” the _ONLY_ charging mode in which you can charge the vehicle on a schedule must also include a departure time. For the vehicle to target the departure time charging it must know the AMP/Current rating of the plug it’s plugged into…so it can predict the kWh it needs to pull and how long that will take…

Well most J-1772 chargers that can dynamically change their current/load start low and ramp up over time - when Porsche “samples” the current it only pulls power for a short while and then shutdowns once it has sampled the possible current - and then waits to start charging at the last minute - well if the current changes over time this calculation will be wrong…

porsche could easily solve the problem by having charging support for:

• ##% battery charge target
• only between these hours x & y

and give up the stupid/complex departure time charging schedule (sometimes I need to leave earlier or later in anycase) why don’t you just charge the car as soon as possible and the wait for me?

Porsche’s charging infrastructure is not world class and their external EVSE’s are not that great- but they sure do charge a lot for them vs. compeition.

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[Jhenson29]

The voltage does not have to be fixed. The EVSE advertises the available current (through the Control Pilot pin of the J1772) so the load (car) doesn't have to figure anything out, just draw less than or equal the advertised current, regardless of voltage.

I was just making a general comment.

I think some people (not you) get confused and think the EVSE controls filling the car, and the car has a passive receptacle like a gas tank (like it’s filling it with electrons or something ?). My point was just that it’s an electrical circuit and for a fixed voltage (which the EVSE is…or at least I mean any change isn’t a controlled change from the EVSE) the load will determine the current. The EVSE is not doing anything to control current.

If your point is just that the voltage doesn’t have to be fixed because the car would continue to vary the load to limit the current anyway, then I agree (within some range…else I assume it throws a fault); it’s just that’s not the point I was trying to make.

 

[Scandinavian]

@daveo4EV, well said about the complex charging. It would have been easier had Porsche in any way had any good instructions about this. I have not been able to figure out what they have been thinking when the designed the complex system. It works but it certainly is not intuitive.

On the charging infra structure I am very disappointed that there has been no update at all from Porsche or VW after their Power Day 9 or whatever the called it). Two of the Porsche dealers close to me have had their HPC’s installed for more than 5 months now, but they are still not operational. And then only available at times when the dealer is open.

Ionity chargers work fine and seem to be much more reliable and better mantained than the EA chargers, but they are too far apart to be a long distance travel support.

Room for improvement, but I doubt it will come anytime soon.

 

[Jhenson29]

since the car must always adhere to the EVSE advertised current, including changing it during the charging session, so the hardware capability to control the current is obviously already in the car.

Yep, that was my point.

 

[mikeva]

OK, thanks folks I have learned even more about how complex this turns out to be.

I am going to go down to VIR (Virginia International Raceway) in early October and the problem is 1) that is about at the limit of my range and 2) there are not really any guaranteed ways to charge at the track. They do have the charging setups for the campers that visit the infield and they happen to be NEMA 14-50 sockets. That is a plus for my PCC+ charger that came with the car.

The rub is that the intel is that while it is 240V 50amp power it is more than a bit 'wonky' at 40 amp but pulling in the low 30's amp range is supposed to be pretty solid.

I know it is not possible, but it sure seems like it should be not that big of a deal to tell the car not to draw the full 40 amps but to back off a little so the grid is not quite so volatile. I have no interest in sitting in my car all night restarting the charging cycle over multiple times during the night. I've gotten spoiled at plugging it in at night and having a full (85%) charge the next morning by 'magic'

 

[Klepper]

OK, thanks folks I have learned even more about how complex this turns out to be.

I am going to go down to VIR (Virginia International Raceway) in early October and the problem is 1) that is about at the limit of my range and 2) there are not really any guaranteed ways to charge at the track. They do have the charging setups for the campers that visit the infield and they happen to be NEMA 14-50 sockets. That is a plus for my PCC+ charger that came with the car.

The rub is that the intel is that while it is 240V 50amp power it is more than a bit 'wonky' at 40 amp but pulling in the low 30's amp range is supposed to be pretty solid.

I know it is not possible, but it sure seems like it should be not that big of a deal to tell the car not to draw the full 40 amps but to back off a little so the grid is not quite so volatile. I have no interest in sitting in my car all night restarting the charging cycle over multiple times during the night. I've gotten spoiled at plugging it in at night and having a full (85%) charge the next morning by 'magic'

You could either run the PMC+ at 50% mode, which would let you charge at 20A instead of 40A, or you could pick up a third party charger (such as this Mustart for under $400) to get up to 32A.

https://www.amazon.com/dp/B077DC39J9/ref=cm_sw_em_r_mt_dp_Z240FR9474T5FZFHR6Z6

 

[whitex]

I was just making a general comment.

I think some people (not you) get confused and think the EVSE controls filling the car, and the car has a passive receptacle like a gas tank (like it’s filling it with electrons or something ?). My point was just that it’s an electrical circuit and for a fixed voltage (which the EVSE is…or at least I mean any change isn’t a controlled change from the EVSE) the load will determine the current. The EVSE is not doing anything to control current.

If your point is just that the voltage doesn’t have to be fixed because the car would continue to vary the load to limit the current anyway, then I agree (within some range…else I assume it throws a fault); it’s just that’s not the point I was trying to make.

Perhaps a simpler way to say it would be:
* Neither the car or the EVSE controls the voltage which can be between 208V-240V nominal, and sometimes a slightly outside that range during normal operation
* EVSE sets maximum current the car is allowed to draw. That limit is updated up to 1000 times per second. Most simple EVSEs keep that limit fixed, but there are some which will vary that limit (for load sharing, schedule, utility hints/restrictions)
* Car draw up to the current limit set by the EVSE, depending on the car's needs. Car is allowed to draw less current, but never more than what EVSE says is available.

 

[daveo4EV]

OK, thanks folks I have learned even more about how complex this turns out to be.

I am going to go down to VIR (Virginia International Raceway) in early October and the problem is 1) that is about at the limit of my range and 2) there are not really any guaranteed ways to charge at the track. They do have the charging setups for the campers that visit the infield and they happen to be NEMA 14-50 sockets. That is a plus for my PCC+ charger that came with the car.

The rub is that the intel is that while it is 240V 50amp power it is more than a bit 'wonky' at 40 amp but pulling in the low 30's amp range is supposed to be pretty solid.

I know it is not possible, but it sure seems like it should be not that big of a deal to tell the car not to draw the full 40 amps but to back off a little so the grid is not quite so volatile. I have no interest in sitting in my car all night restarting the charging cycle over multiple times during the night. I've gotten spoiled at plugging it in at night and having a full (85%) charge the next morning by 'magic'

• if you have a PMC+ you can run in 50% mode - which will lower the amps to 20 amps which should greatly increase charging relaibliity but charge slower
• if you have/beg/borrow/steal a PMCC you can adjust the amps using the LCD screen 32-36 amps should do the trick to improve reliability
• you can buy an alternative mobile charger with greater adjustability and use it instead - mustart is a good choice since’s a 32 amp maximum charger even with a NEMA 14-50 plug

I have similiar problems at thunderhill raceway and often have to tweak the charging amps to keep the poorly maintained breakers from pop’ing

you could also do the following:

• obtain a 14-30 30 amp supply cable for the PMC+/PMCC from Audi/VW/Porsche
• obtain a NEMA 14-50 to NEMA 14-30 adapter from amazon
• put the 14-30 supply cable on your PMC+/PMCC - this will tell/lie to the PMC+/PMCC that you are using a 30 amp circuit
• plug the PMC+/PMCC into the Amzon adapter your purchased - plug the adapter into the VIR NEMA 14-50 plugs
• since the PMC+/PMCC has a 30 amp supply cable connected to it will only pull 24 amps
  • it doesn’t “know/see” the 14-50 plug or adapter - since it takes the max amp settings from the VW/Audi/Porsche supply cable you have directly attached to the PMC+/PMCC

 

[daveo4EV]

there are some decently reliable chargers in nearby Danvile - but wow VIR is a fast charging wasteland!!!

 

[NC_Taycan]

you could also do the following:

• obtain a 14-30 30 amp supply cable for the PMC+/PMCC from Audi/VW/Porsche
• obtain a NEMA 14-50 to NEMA 14-30 adapter from amazon
• put the 14-30 supply cable on your PMC+/PMCC - this will tell/lie to the PMC+/PMCC that you are using a 30 amp circuit
• plug the PMC+/PMCC into the Amzon adapter your purchased - plug the adapter into the VIR NEMA 14-50 plugs
• since the PMC+/PMCC has a 30 amp supply cable connected to it will only pull 24 amps
  • it doesn’t “know/see” the 14-50 plug or adapter - since it takes the max amp settings from the VW/Audi/Porsche supply cable you have directly attached to the PMC+/PMCC

The RV pedestals at VIR have both 14-30 and 14-50 outlets, so you can also do this without having to buy an adapter. This should give you 24A charging current (80% of maximum rated circuit load).

I did find that I wanted the extension though since the pedestals are outdoors, high off the ground, so the EVSE is exposed to the elements. With the 14-50 RV extension (bought on Amazon - not inexpensive!) I put the charger in one of the bins I bring to pack other stuff, and it's now protected from the inevitable rains that roll through VIR, at least whenever I'm there.

@mikeva it's way out of your way, but there is an EA station with multiple 150 kW and one 350 kW tower 44 miles away from VIR (44 miles precisely the wrong direction for you) at Sheetz in Hillsboro, NC. If you decide to go that route, I'd be happy to follow you there Monday night in case you cut it too close on the range. I know I will be cutting it close...

 

[schad]

The RV pedestals at VIR have both 14-30 and 14-50 outlets, so you can also do this without having to buy an adapter.

Are you certain it's a 14-30 outlet? RVs use 30A 120V (which apparently is called TT-30R).

 

[NC_Taycan]

No, I am not certain that it is not TT-30R. IIRC (and the RC part of that is in question), some of the paddock pylons have two ganged breakers for this outlet - which makes me think it's 240V, but some also have a single breaker. Looking at this cheat sheet here NEMA Plug Chart - NEMA Plug Straight Blade Reference Chart | StayOnline it could be 7-20, 10-20, 10-30. Don't think it's 10-50, and don't think it's any of the three phase plugs. So not sure any of this helps. But I am 100% certain 14-50 is available, subject to previous cautions about the quality being in question when pulling more than 30A.

 

[TaycanCook]

Adding to this thread, for campground plugs that use the 30amp 120 receptacle, what would happen when using a "tt-30P to a 14-50R" adapter with the PMC+ (using 14-50P) set at 50%?

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