Why does the TeslaTap work?

[daveo4EV]

short answer - TLDR; - because it actually doesn't do much of anything since both types of chargers (Tesla and J-1772) are fundamentally the same behind the different shaped plugs.

if you pull back the curtain - the wizard behind the stage is the same as every other North American J-1772 charger…2 ac connectors, 2 communications "connectors", 1 electrical ground.

details below…

we all should know about the TeslaTap - but how/why does it work - well I've got a little diagram here that I think will demystify for most people - the short answer is the TeslaTap works because the Tesla AC chargers really are exactly functional J-1772 chargers in North America - the honestly and factually just have the wrong shaped plug…electrically they have all the same connections and protocols electrically to charge any EV if you can adapt the plug shape…

see my diagram below and I think you'll see it's pretty simple really once you get past the physical shape differences…

Both Tesla and J-1772 have 5 electrical connections:

• L1 - 120V "hot" high voltage power
• L2 - 120V "hot" high voltage power
  • L1 + L2 = 120V + 120V = 240V
  • in the case of L1 charging (120V power sources) - the L2 connector is 120V neutral - like your home plug outlets - standard North American 120V AC power neutral.
• Control Contact - a low voltage communications connector
• Control Proximty - a low voltage communications connector
• Ground - electrical ground conductor

NOTE: part of the safety of the J-1772 EV charging standard is that there is NO high voltage power on L1/L2 connectors unless Control/Contact/Proximity actually have a detected electrical connection - the voltage/power on these connects is low enough and weak enough that they pose less of a risk than a 1.5V AAA battery - so you can drop the connector in a puddle of water and nothing will happen because Control/Contact/Proximity will not detect/show they are communicating with a vehicle - this a major safety feature of J-1772 and it's interesting to note Tesla's connector and behavior and protocol follow the same standards…

for L1/L2 charger both Tesla and J-1772 actually use all the connectors for exactly the same purposes - and the L1/L2 are "raw" AC power in both cases - AC power is the same for everyone - Tesla and/or Taycan - and Tesla chargers (Tesla Wall Chargers and Tesla UMC's (Gen1 & Gen2) "speak" Control Contact & Control Proximty - same as J-1772 same as PMC+/PMCC) - Electrical Ground is physically identical it has to be cause ya'know electricity works the same for everyone - there is no "special" ground - ground is ground.

so I think you can see the adapter is really quite simple - because at the end of the day Tesla chargers are just J-1772 chargers with the wrong shaped connector - but internally and electrically they are actual functionality identical.

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[Klepper]

Great explanation, thanks!

 

[daveo4EV]

Tesla Superchargers use the same 5 connectors - but in the case of superchargers:

• L1 & L2 are high voltage DC (not AC) - 200V each? any EE's wanna weigh in here?
• Control Contact and Control Proximity are a proprietary digital (vs. J-1772 analog) protocol - unique to Tesla
• Ground is still Ground

I've shown a North American Tesla Charging connector below - this the same connector/plug for AC L1/L2 charging and FastDC L3 charging unto 220 kW - Tesla used the same connector for both AC charging and DCFast Charging…

to open the North American supercharger network will require Tesla to either "add" CCS cables to every supercharger (possible) or make an adapter that converts there small connect to the SAE/CCS connector (also possible)…

it's in my opinion a clever repurposing of the exiting 5 connector layout - but running high voltage DC over L1 & L2 and digital communications protocol across Control/Contact/Proximity is a "violation" of the J-1772 standard- but allowed Tesla to have one 5 pin connector work for both AC and DC charging and kept their connector smaller and more manageable so that humans can actually handle it vs. the abomination that is the SAE/CCS connector…

you can see the SAE/CCS connector picture below - the two L1/L2 connectors are unused/wasted space - the two control connectors are used, and the ground is present - but the high voltage DC connectors are "hung" off the bottom - separate from the L1/L2 AC connectors - this makes the connector un-necessarily large and unwieldy in my opinion - I really admire Tesla for reusing the L1/L2 connectors for FastDC charging - given the two communications protocols are different the car is always in a position to "know" if the high voltage lines will be AC or DC - and it allows the connector to be smaller and more manageable for a slight increase in protocol complexity where the car has to be able to handle AC or DC power on the same input connectors…

the picture below should also tell you a lot about why the adapter, or connector to bridge Supercharger to CCS is going to be "interesting" to watch play out in North America.

 

[daveo4EV]

Posting #1 should also tell the informed reader/viewer why it's so easy for Tesla to ship a J-1772 adapter with each Tesla vehicle sold - again all you have to do is bridge the same 5 electrical connections…

every Tesla ships with a J-1772 adapter so that Model S/Model X/Model 3/Model Y can use public AC L1/L2 chargers…they again rely on the fact that behind the different shaped connector Tesla is fundamentally a J-1772 L1/L2 charging vehicle…

https://shop.tesla.com/product/sae-j1772-charging-adapter

the adapter pictured below is provided to each Tesla vehicle owner and lets them use public J-1772 chargers…

it is the functional mirror of a TeslaTap

TeslaTap let's J-1772 based vehicles use Tesla EVSE's
Tesla's J-1772 adapter lets Tesla Vehicles use J-1772 EVSE's (like the PMC+/PMCC)

 

[daveo4EV]

short answer - TLDR; - because it actually doesn't do much of anything since both types of chargers (Tesla and J-1772) are fundamentally the same behind the different shaped plugs.

if you pull back the curtain - the wizard behind the stage is the same as every other North American J-1772 charger…2 ac connectors, 2 communications "connectors", 1 electrical ground.

details below…

we all should know about the TeslaTap - but how/why does it work - well I've got a little diagram here that I think will demystify for most people - the short answer is the TeslaTap works because the Tesla AC chargers really are exactly functional J-1772 chargers in North America - the honestly and factually just have the wrong shaped plug…electrically they have all the same connections and protocols electrically to charge any EV if you can adapt the plug shape…

see my diagram below and I think you'll see it's pretty simple really once you get past the physical shape differences…

Both Tesla and J-1772 have 5 electrical connections:

• L1 - 120V "hot" high voltage power
• L2 - 120V "hot" high voltage power
  • L1 + L2 = 120V + 120V = 240V
  • in the case of L1 charging (120V power sources) - the L2 connector is 120V neutral - like your home plug outlets - standard North American 120V AC power neutral.
• Control Contact - a low voltage communications connector
• Control Proximty - a low voltage communications connector
• Ground - electrical ground conductor

for L1/L2 charger both Tesla and J-1772 actually use all the connectors for exactly the same purposes - and the L1/L2 are "raw" AC power in both cases - and Tesla chargers (Tesla Wall Chargers and Tesla UMC's (Gen1 & Gen2) "speak" Control Contact & Control Proximty - same as J-1772) - Electrical Ground is physically identical it has to be cause ya'know electricity works the same for everyone - there is no "special" ground - ground is ground.

so I think you can see the adapter is really quite simple - because at the end of the day Tesla chargers are just J-1772 chargers with the wrong shaped connector - but internally and electrically they are actual functionality identical.

this is why Tesla Wall Chargers (Tesla Destination Chargers) and Tesla UMC's can charge any J-1772 EV via an adapter - they _ARE_ J-1772 EVSE's with a funny shaped plug. But they are electrically identical to J-1772 chargers from ClipperCreek/PMC+/PMCC/ChargePoint/JuiceBox/etc…

 

[KTC]

I really admire Tesla for reusing the L1/L2 connectors for FastDC charging - given the two communications protocols are different the car is always in a position to "know" if the high voltage lines will be AC or DC - and it allows the connector to be smaller and more manageable for a slight increase in protocol complexity where the car has to be able to handle AC or DC power on the same input connectors…

What's the max wattage that will go through the Tesla interface and cabling? Can it go up to 350kW or will it need more cross sectional area?

 

[daveo4EV]

Tesla already makes a CCS adapter to allow Tesla Vehicles in certain markets to use CCS chargers…to my knowledge they are not yet shipping or supporting this adapter/connector in North America…

https://electrek.co/2020/12/16/tesla-announces-new-ccs-charging-adapter/
https://www.tesla.com/sites/default/files/CCS/CCS_Combo_2_Adapter_en.pdf

adapter to allow Teslas to use CCS chargers shown below…

 

[daveo4EV]

What's the max wattage that will go through the Tesla interface and cabling? Can it go up to 350kW or will it need more cross sectional area?

• Tesla's AC 240V EV on board charging supports upto 19.2 kW same as J-1772 standard
  • Tesla Model 3/Model Y support up to 48 amp of charging - 60 amp breaker
  • Historically Model S/Model X supported upto 72/80 amps via optional factory installed onboard charger upgrades
  • they have changed this mix of charging speeds so many times I've lost track
  • Model 3 short range and based model S/X in the past have sometimes only supported 32/40 amp charging (40/50 amp breakers)
  • consult the current Tesla.com configurator for what they are doing today - cause they change it up so much.
• Tesla Gen1 Wall Chargers supported 20-100 amp configuration for AC L2 charging
• Tesla Gen2 Wall Chargers supported 20-100 amp configuration for AC L2 charging
• Tesla Gen3 Wall Chargers support 16-60 amp configurations for AC L2 charging
• Tesla Gen1 Universal Mobile Chargers were upto 40 amps @ 240V - 50 amp breaker
  • various NEMA plug adapters were/are available for wide range of NEMA plug compatibility
• Tesla Gen2 Universal Mobile Chargers are upto 32 amps @ 240V - 40 amp breaker
  • various NEMA plug adapters are available for wide range of NEMA plug compatibility
• Tesla's V3 superchargers support upto 250 kW DC charging @ 400'ish volts (440 volts?)

https://www.tesla.com/blog/introducing-v3-supercharging

https://www.caranddriver.com/news/a32132062/tesla-250-kw-vs-150-kw-supercharger-tested/

 

[daveo4EV]

Tesla's AC charging supports upto 19.2 kW same as J-1772 standard
Tesla's V3 superchargers support 250 kW DC charging @ 400'ish volts (440 volts?)

https://www.tesla.com/blog/introducing-v3-supercharging

https://www.caranddriver.com/news/a32132062/tesla-250-kw-vs-150-kw-supercharger-tested/

however I'm betting with the proper protocol changes to the communication connectors Tesla could distinguish between 400 and 800V charging and do the "right" thing to go beyond 250 kW - 800V should allow more current across the same sized existing connectors that can handle 400V DC @ 250 kW…

• older Tesla model vehicles would be limited to 400V (probably - maybe not)
• but certainly newer Tesla models could support 400/800V FastDc charging just like the Taycan does today
  • but would most likely require some hardware changes to the onboard DC chargers
• vehicle software would obviously need to be updated to support this

I see no reason technically why Superchargers couldn't support both 400/800V charging - but would obviously required software/hardware changes/upgrades and they would need to support backwards compatibility with the existing fleet of non-800V Tesla EV's.

I'm certain if business agreements were in place the engineering could be done to make both CCS and Tesla's support both 400V and 800V charging - it's the legal and business agreeements (and business incentives) that are lacking - not the engineering/technical capacity to solve the problem(s).

nothing here is technically impossible or even that complex - the complexity is all in the business standards and ego's and chest thumping - the customers lose out in this case.

the industry lacks the proper motivation to do the right thing here which is make all of this work seamlessly…

 

[daveo4EV]

short answer - TLDR; - because it actually doesn't do much of anything since both types of chargers (Tesla and J-1772) are fundamentally the same behind the different shaped plugs.

if you pull back the curtain - the wizard behind the stage is the same as every other North American J-1772 charger…2 ac connectors, 2 communications "connectors", 1 electrical ground.

details below…

we all should know about the TeslaTap - but how/why does it work - well I've got a little diagram here that I think will demystify for most people - the short answer is the TeslaTap works because the Tesla AC chargers really are exactly functional J-1772 chargers in North America - the honestly and factually just have the wrong shaped plug…electrically they have all the same connections and protocols electrically to charge any EV if you can adapt the plug shape…

see my diagram below and I think you'll see it's pretty simple really once you get past the physical shape differences…

Both Tesla and J-1772 have 5 electrical connections:

• L1 - 120V "hot" high voltage power
• L2 - 120V "hot" high voltage power
  • L1 + L2 = 120V + 120V = 240V
  • in the case of L1 charging (120V power sources) - the L2 connector is 120V neutral - like your home plug outlets - standard North American 120V AC power neutral.
• Control Contact - a low voltage communications connector
• Control Proximty - a low voltage communications connector
• Ground - electrical ground conductor

NOTE: part of the safety of the J-1772 EV charging standard is that there is NO high voltage power on L1/L2 connectors unless Control/Contact/Proximity actually have a detected electrical connection - the voltage/power on these connects is low enough and weak enough that they pose less of a risk than a 1.5V AAA battery - so you can drop the connector in a puddle of water and nothing will happen because Control/Contact/Proximity will not detect/show they are communicating with a vehicle - this a major safety feature of J-1772 and it's interesting to note Tesla's connector and behavior and protocol follow the same standards…

for L1/L2 charger both Tesla and J-1772 actually use all the connectors for exactly the same purposes - and the L1/L2 are "raw" AC power in both cases - AC power is the same for everyone - Tesla and/or Taycan - and Tesla chargers (Tesla Wall Chargers and Tesla UMC's (Gen1 & Gen2) "speak" Control Contact & Control Proximty - same as J-1772 same as PMC+/PMCC) - Electrical Ground is physically identical it has to be cause ya'know electricity works the same for everyone - there is no "special" ground - ground is ground.

so I think you can see the adapter is really quite simple - because at the end of the day Tesla chargers are just J-1772 chargers with the wrong shaped connector - but internally and electrically they are actual functionality identical.

this is also why NEMA 14-50 and 6-50 are the same electrically to any North American EVSE - looking at the diagram above there is no electrical connection for the NEMA 14-50 “neutral” connector/wire…

there is L1/L2 - which correspond to the two “hot” connectors on the NEMA 14-50/6-50 plug types, there is electrical ground (the same on the 14-50/6-50) - and the two extra connectors (Control/Contract/Proximity) are for the EV charger (EVSE) - the neutral connector on the NEMA 14-50 connector has no ”purpose/role” in EV charging or any actual connector in the J-1772 connector standard…

this is the same for NEMA 14-30 vs. 6-30/10-30 - only different is amps 30 vs. 50 - again no neutral purpose/role in the EV vehicle connector.

 

[TycanNewHampshire]

good info....so far, I have only seen one Tesla charging at an EA/non-Tesla charger, personally. This was this past month.
It was connected to the Lv2 (slow) charger with a tesla-tap adapter and needless to say, they were charging when I pulled up and still charging when I left

 

[NC_Taycan]

How certain is anyone that Tesla Superchargers use DC and not AC? I don't know one way or the other - but it would conceptually be easier to design the charging infrastructure in the car if it only ever had to accept AC.

That said, the existence of a CCS to Tesla adapter pretty strongly suggests they are indeed using DC in that case...

 

[daveo4EV]

How certain is anyone that Tesla Superchargers use DC and not AC? I don't know one way or the other - but it would conceptually be easier to design the charging infrastructure in the car if it only ever had to accept AC.

That said, the existence of a CCS to Tesla adapter pretty strongly suggests they are indeed using DC in that case...

superchargers are DC - on board ac/dc charger can handle neither volts or amps for up to 250 kw

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