Questions about Tesla AC charging and J1772

[jstjohnz]

These questions are theoretical, I'm just trying to get a better understanding of how things work.

I have read that Tesla uses J1772 protocol for AC charging. This seems logical, and seems to be supported by the fact that the Tesla-supplied J1772 adapter, seems to be a physical adapter only, but wired straight through. (I have heard that, do not know if true.)

If this is the case, then why does the gen 2 HPWC have a dip switch to select TESLA or J1172 mode?

What does that switch do exactly?

Why are 'reverse' adapters, (to go from a J1772 vehicle to a Tesla wall connector) so expensive?

-jim-

 

[miimura]

The Wall Connector can also talk to the car digitally over the power line. The switch eliminates the time that it attempts to do that communication. European Wall Connectors can also prevent charging if the digital communication is not successful.

The reverse adapters (Tesla Tap, Jdapter, etc.) are expensive mostly because the Tesla inlet is not manufactured in volume for third parties to use for this kind of product. Parts for J1772 plugs and inlets can be readily purchased from China to make things like J1772 extension cables.

 

[nwdiver]

If this is the case, then why does the gen 2 HPWC have a dip switch to select TESLA or J1172 mode?

??? What dip switch are your referring to? The only switches on the Gen 2 HPWC are for voltage and current settings.

 

[jstjohnz]

The Wall Connector can also talk to the car digitally over the power line. The switch eliminates the time that it attempts to do that communication. European Wall Connectors can also prevent charging if the digital communication is not successful.

The reverse adapters (Tesla Tap, Jdapter, etc.) are expensive mostly because the Tesla inlet is not manufactured in volume for third parties to use for this kind of product. Parts for J1772 plugs and inlets can be readily purchased from China to make things like J1772 extension cables.

Thank you, very helpful.

 

[jstjohnz]

??? What dip switch are your referring to? The only switches on the Gen 2 HPWC are for voltage and current settings.

View attachment 586799

??? What dip switch are your referring to? The only switches on the Gen 2 HPWC are for voltage and current settings.

View attachment 586799

my question was based on information I saw in another thread. I don’t have first-hand information about the DIP switch or which specific model of wall connector it is on. It may not be labeled as to function.

 

[mociaf9]

??? What dip switch are your referring to? The only switches on the Gen 2 HPWC are for voltage and current settings.

View attachment 586799

It's switch #2 (the one on the right), which Tesla's manual says to always leave in the ON/up position. But if you put it in the OFF/down position, the HPWC doesn't try to do its digital handshake with the car. That allows one to use a straight mechanical/electrical adapter to go from the tesla plug to a J1772. With the switch in the ON/up position, you need an adapter that will spoof the handshake before the HPWC will provide charge.

 

[nwdiver]

It's switch #2 (the one on the right), which Tesla's manual says to always leave in the ON/up position. But if you put it in the OFF/down position, the HPWC doesn't try to do its digital handshake with the car. That allows one to use a straight mechanical/electrical adapter to go from the tesla plug to a J1772. With the switch in the ON/up position, you need an adapter that will spoof the handshake before the HPWC will provide charge.

Interesting... so the sole purpose of that switch is to keep non-Teslas from using the HPWC? I bought a Tesla => J1772 adapter... I was wondering why it didn't work with the HPWC.

 

[mociaf9]

Interesting... so the sole purpose of that switch is to keep non-Teslas from using the HPWC? I bought a Tesla => J1772 adapter... I was wondering why it didn't work with the HPWC.

Tesla chose to change to a different signalling than the legacy J1772. I'm not sure why. One of the results was that most adapters would no longer work on them unless you knew and were able to change that dip switch setting. Though, I think they may have still worked if you just left them plugged in for a long enough time. I think the HPWC tries to use the new signals for 30 sec. or a minute and then will listen for the legacy J1772 signal if you're still trying to charge. I don't know how well this works though. Better to just change the dip switch so it only uses the J1772 signalling in the first place.

 

[jstjohnz]

Is this switch also on gen3 or just gen2?

 

[Rocky_H]

It's not in a Gen 3.