What do these markings mean on my EVSE charging cable?

[KLHubb]

Currently, I have a 100 amp service in my garage, and the Porsche charger that came with the 2020 4S. Adjusting to 39 amps, I get plus or minus 8.4 watts at the car during normal charging. None of the cables get more than warm. I have concluded that I will upgrade the service when I am able to own a Cayman E, which no doubt will be able to charge at a higher rate. I don't think it will be worth doing more for now, although I suppose could push things up to 50 amps by installing a 60 amp breaker. As I recall the charger will do 50 amps, however, that might trigger the worrisome cable heating problem.

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[daveo4EV]

Currently, I have a 100 amp service in my garage, and the Porsche charger that came with the 2020 4S. Adjusting to 39 amps, I get plus or minus 8.4 watts at the car during normal charging. None of the cables get more than warm. I have concluded that I will upgrade the service when I am able to own a Cayman E, which no doubt will be able to charge at a higher rate. I don't think it will be worth doing more for now, although I suppose could push things up to 50 amps by installing a 60 amp breaker. As I recall the charger will do 50 amps, however, that might trigger the worrisome cable heating problem.

the Porsche PCM+/PMCC is maximum 9.6 kw (40 amps) in north America - if you doubt me look at the sticker on the back of the unit - it clearly listed the max amps and KW's as 40/9.6 kW…the PMC+/PMCC will _NOT_ do 48 or 50 amp charge rate…

The Porsche Wall Charger is wall mounted hardwired EVSE than is adjustable from 15-80 amps (20 to 100 amp breaker)

if you want 48/50 amp you will need to purchase a non-mobile EVSE and install a 60 or 70 amp breaker and appropriate write gauge to match the breaker.

ChargePoint Flex is a 50 amp EVSE - and that install requires hardwiring and a 70 amp breaker.

There are several excellent 48-64 amp (60-80 amp breaker) EVSE's for North American market.

the maximum charge rate of your Taycan is 11 kW (48 amps) unless you purchased the 19.2 kW factory option when you ordered the vehicle.

 

[KLHubb]

Thanks for the information,...I stand corrected on the 40 amps matter.
I have never seen the charger deliver 9.6 kw to the vehicle....it usually settles out around 8.4 kW, when adjusted to 40 amps, but 9.6 kW would be nice.
I am wondering why I am not getting 9.6 kW at 40 amps on this charger?
I don't have the 19.2 kW factory, and really don't need it....I am simply interested in making optimal use of my existing equipment.

 

[daveo4EV]

Thanks for the information,...I stand corrected on the 40 amps matter.
I have never seen the charger deliver 9.6 kw to the vehicle....it usually settles out around 8.4 kW, when adjusted to 40 amps, but 9.6 kW would be nice.
I am wondering why I am not getting 9.6 kW at 40 amps on this charger?
I don't have the 19.2 kW factory, and really don't need it....I am simply interested in making optimal use of my existing equipment.

you are getting 9.6 kW "raw" - 8.4 kW is the effective rate of charge @ the battery as reported by the Porsche in car software/display - there is "loss" in AC/DC conversion and other normal factors when charging a battery - so 8.4-8.6 kW is about "right" for a 9.6 kw 'raw' feed…if you were only getting 8.4 kw from the Porsche charger - you'd see 7.2 kW "in the car"...

the number you see in the car is not the "raw" power feed - it's the effective rate after losses…

it's common, fully expected, and normal.

 

[juergenhr]

The Grizzl-E classic I just received is using an AWG 8 for the current carrying conductors and an AWG 10 for the ground conductor 600V 105C UL approved on a NEMA 6-50 plug. The cable to the car has an AWG 10 ground and 4 AWG 12 cables, two of which are connected to L1 and the other two to L2 there is also an AWG 18 signal cable. this is 300V rated and 105C. Two AWG12 cables have a combined cross section of 6.6 mmsq. vs 5.26mmsq. for AWG 10, so greater Ampacity but less than AWG 8 which is 8.37 mmsq. Even thogh the AWG 10 cable at 105C is correct, Porsche also overlooked the fact that some folks (like me) use the wall mount. I found I need to leave the door open as there is no ventilation and it gets way too hot from the cable causing a overheat fault in the charger. I'll probably drill some large diameter holes in the top and bottom to alleviate that.

 

[daveo4EV]

The Grizzl-E classic I just received is using an AWG 8 for the current carrying conductors and an AWG 10 for the ground conductor 600V 105C UL approved on a NEMA 6-50 plug. The cable to the car has an AWG 10 ground and 4 AWG 12 cables, two of which are connected to L1 and the other two to L2 there is also an AWG 18 signal cable. this is 300V rated and 105C. Two AWG12 cables have a combined cross section of 6.6 mmsq. vs 5.26mmsq. for AWG 10, so greater Ampacity but less than AWG 8 which is 8.37 mmsq. Even thogh the AWG 10 cable at 105C is correct, Porsche also overlooked the fact that some folks (like me) use the wall mount. I found I need to leave the door open as there is no ventilation and it gets way too hot from the cable causing a overheat fault in the charger. I'll probably drill some large diameter holes in the top and bottom to alleviate that.

the Porsche PMCC Dock combination EVSE mini-sauna was also a poorly thought out exercise in terms of heat retention with a product who's engineering specifications call for a 90F+ thermal delta above ambient - there frankly is an insufficient amount of thermal mass in terms of static air volume with no circulation inside the PMCC dock enclosure…

Much like Obi Wan Porsche's failure in this space is complete and they are now paying the price with this recall…

 

[ShiftyWolf]

Once the dust settles, I'm curious if Porsche/Audi will continue providing plug in EVSEs or just quietly begin issuing charger vouchers to future car buyers.

In the end, I suppose it really just comes down to cost versus profit.

 

[daveo4EV]

I would expect them to drop them all together like Tesla - you don't need one of these per-EV and they are generic like USB chargers…but yeah - this will be a fading problem eventually.

 

[KLHubb]

you are getting 9.6 kW "raw" - 8.4 kW is the effective rate of charge @ the battery as reported by the Porsche in car software/display - there is "loss" in AC/DC conversion and other normal factors when charging a battery - so 8.4-8.6 kW is about "right" for a 9.6 kw 'raw' feed…if you were only getting 8.4 kw from the Porsche charger - you'd see 7.2 kW "in the car"...

the number you see in the car is not the "raw" power feed - it's the effective rate after losses…

it's common, fully expected, and normal.

Thanks for clarifying raw feed versus kW in the car. That's quite a loss....over the course of full charge (10 hrs) the losses amount to 10 kW, correct? I imagine someone is looking into how to mitigate those losses.

 

[daveo4EV]

Thanks for clarifying raw feed versus kW in the car. That's quite a loss....over the course of full charge (10 hrs) the losses amount to 10 kW, correct? I imagine someone is looking into how to mitigate those losses.

the losses are inline with industry norms and the "cost of doing business" for AC charging to a DC battery - I would not expect very much improvement in this space, but I'm open to being surprised - most AC/DC converters are 92% efficient - so 9.6 kW going "in" will equal 8.8 kW going "out" to the battery - solar inverters that converted DC to AC are 93-95% efficient…

what ever isn't AC/DC loss conversation is the cost of "running systems" to keep them awake during the charging process - there is a 12V DC/DC converter to keep the 12V battery charged, and then there is running the PCM/Celluar stuff on the car and some losses due to resistance/heat/impedance…

oh and lets not forget any thermal management that heats/cools the battery during the charging process for battery longevity/health - you can sometime hear/feel exhaust fans running on a Taycan during a charging session - running these components all comes from the power system of the vehicle - either the 12V system or the main battery - this all results in "overhead" of the charging process…

10% loss for charging overhead is pretty much where we're at and I don't expect any major improvements - we might be able to get down to less overhead loss outside the scope of the AC/DC conversion losss (running lower power computers keeping the car "awake" during the charing process) but now we're in cost/benefit analysis…

 

[KLHubb]

the losses are inline with industry norms and the "cost of doing business" for AC charging to a DC battery - I would not expect very much improvement in this space, but I'm open to being surprised - most AC/DC converters are 92% efficient - so 9.6 kW going "in" will equal 8.8 kW going "out" to the battery - solar inverters that converted DC to AC are 93-95% efficient…

what ever isn't AC/DC loss conversation is the cost of "running systems" to keep them awake during the charging process - there is a 12V DC/DC converter to keep the 12V battery charged, and then there is running the PCM/Celluar stuff on the car and some losses due to resistance/heat/impedance…

oh and lets not forget any thermal management that heats/cools the battery during the charging process for battery longevity/health - you can sometime hear/feel exhaust fans running on a Taycan during a charging session - running these components all comes from the power system of the vehicle - either the 12V system or the main battery - this all results in "overhead" of the charging process…

10% loss for charging overhead is pretty much where we're at and I don't expect any major improvements - we might be able to get down to less overhead loss outside the scope of the AC/DC conversion losss (running lower power computers keeping the car "awake" during the charing process) but now we're in cost/benefit analysis…

Yes, we will have to wait for new materials technology....high temp superconductors(dream on!)
Do the losses vary with voltage? Would higher voltage help?
I suppose larger conductors would help a bit, but at a cost/weight penalty.

 

[daveo4EV]

Yes, we will have to wait for new materials technology....high temp superconductors(dream on!)
Do the losses vary with voltage? Would higher voltage help?
I suppose larger conductors would help a bit, but at a cost/weight penalty.

we are now beyond my general engineering knowledge - I'm CS degree and highly technical and have EE friends and general exposure to EE issues, but as to what can be done to specifically "improve" things in this space I'm not your information source

I have researched this stuff out of curiosity and found that industry wide Porsche's charging effciencey is about the same other's Tesla, Lucid, Rivian etc…how much power from the "raw" feed actual results in KWH's being added to the battery is one of the industries hidden spec's - it's not quite a full on secret - but no one is rushing to educated customers that there is about a 10% loss to charge your EV - so 80 kWh of power in your battery routinely yields about 88 kWh on your local providers electrical meter…as part of the charing session.

 

[KLHubb]

Well, not exactly a scandal, but an opportunity to further improve the efficiency of the technology....certainly an improvement over the efficiency of an internal combustion engine.

 

[Jhenson29]

Do the losses vary with voltage? Would higher voltage help?

Yes, higher voltages would help. If I had to hazard a guess, something around 565VAC would mean they could straight rectify with no other voltage conversion minus whatever the BMS needs to do. But you don’t have that natively (Canada does 575VAC as their standard 3-phase, but that wouldn’t be residential). So, you’d have to boost the voltage somewhere. Kind of just kicking the can down the road. Or up the road I guess, in this case. There would be some savings in the cable losses between where it’s boosted and the car though. Losses there are though heat and heat comes from current across resistance (in this case, the wire).

I think over a long enough distance, those cable savings outweigh the transformer cost. This is one reason why power distribution is such high voltage. Less materials being the other. I don’t know how much each factors as I don’t work in that domain.

But even on our processing lines, we do control power distribution with 120VAC while all of the control voltage used is actually 24VDC. The reason being how much larger the wire would be for 24VDC distribution at the same power. Plus voltage drops across long distances.

 

[KLHubb]

Yes, higher voltages would help. If I had to hazard a guess, something around 565VAC would mean they could straight rectify with no other voltage conversion minus whatever the BMS needs to do. But you don’t have that natively (Canada does 575VAC as their standard 3-phase, but that wouldn’t be residential). So, you’d have to boost the voltage somewhere. Kind of just kicking the can down the road. Or up the road I guess, in this case. There would be some savings in the cable losses between where it’s boosted and the car though. Losses there are though heat and heat comes from current across resistance (in this case, the wire).

I think over a long enough distance, those cable savings outweigh the transformer cost. This is one reason why power distribution is such high voltage. Less materials being the other. I don’t know how much each factors as I don’t work in that domain.

But even on our processing lines, we do control power distribution with 120VAC while all of the control voltage used is actually 24VDC. The reason being how much larger the wire would be for 24VDC distribution at the same power. Plus voltage drops across long distances.

Our village manages a waste treatment plant, and I'm curious to know what voltage it uses in its processes. I assume that it's multiples of 240V. I am not familiar with what the village transformers are running at...... In any case, it's just curiousity.
I wonder whether the general move to ubiquitous use of electricity will prompt reconsideration of power grid distribution strategies. While it may be the inevitable cost of doing business, it seems to me that these losses across the grid result in a huge energy waste.

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