J1772 charging blues

[ChargeIt!]

Well it appears that older Teslas need a firmware update to work with the Nissan Aero J1772 charging stations. As of late May the firware was not available and I was just told it was being worked on.

I did find a Columb and Eaton brand chargers and both worked with my #255 Roadster. They were both limited to 30 amps but that is far better than the 110V adapter.

1.5 Roadsters (VIN<=500) with recently released firmware 3.6.7.11 now work with the AeroVironment ("AV") EVSEs typically found at Nissan Dealers. The Roadster automatically respects the AV EVSE's 30A pilot signal.

[S-2000 Roadster]

Certainly possible and rather inexpensive, but unless Tesla adds a 30 amp charge rate selection to the firmware you are stuck with only being able to use 24 amp charging at all the 30 amp charge spots.

What I find confusing is that people talk about 50-amp at RV parks and with the UMC, but codes specify that the maximum current draw is 80% of that, or only 40 amps. The Tesla Roadster screen shows the actual current, 40 amps, not the rated current of 50 amps. I discovered this the hard way after building a NEMA 14-50 extension from my breaker box that was literally capable of carrying 50 amps, only to be disappointed when I "only" got 40 amps on the Tesla screen.

So, when the discussion turns to J1772 charging and 30-amp capable systems, are we actually talking about 24 amps on the Roadster screen anyway? 24 amps happens to be exactly 80% of the 30-amp rating, so I don't think Tesla Motors needs to change the firmware at all.

Now that there are several electric car brands on the road and various charging stations, I hope that there is a standard for discussing current ratings versus actual current draw.

[richkae]

Scott451 posted this:
An EV is allowed to draw 80% of the breaker rating as a continous load. Since the breakers are all increments of 10A, using a 30A,40A,50A,60A breaker gives 24A, 32A, 40A, 48A charging current. The UL (Underwriters Labs) screwed this all up when the refused to certify the ITT cannon J1772 plug for 32A [ref?]. They only allowed 30A, so now we're stuck with a bunch of 30A chargers on a 40A circuit.
In this thread:
Tesla/J1772 adapter available from Tesla's website
Because of that, it is hard to know whether a 30amp charger is really a 30 amp breaker with a 24 amp max, or a 40 amp breaker with a 30 amp max.
If it was 32, it would be obvious. I think you can usually assume its a 40 amp breaker with a 30 amp max.

[vfx]

That would be hard to change. Everyone talks about 100 percent. Asking the world to all change to 80% is not likely.

[scott451]

So, when the discussion turns to J1772 charging and 30-amp capable systems, are we actually talking about 24 amps on the Roadster screen anyway? 24 amps happens to be exactly 80% of the 30-amp rating, so I don't think Tesla Motors needs to change the firmware at all.

J1772 30A charging refers to the "pilot" signaled by the EVSE to the charger(in the roadster). Using the Tesla J1772->Roaster charging cable will allow you to charge at the full current signaled by the EVSE. (in this case 30A). Using an eBay J1772->NEMA 14-50 connected to your UMC/RFMC will only allow you to charge at 24A because the VDS does not allow 30A. I think Tesla should add 30A to the VDS. But until they do, [SHAMELESS PLUG]The Telsa Tattler allows you to set 30A.[/SHAMELESS PLUG]

[TEG]

J1772 30A charging refers to the "pilot" signaled by the charger. Using the Tesla J1772->Roaster charging cable will allow you to charge at the full current signaled by the charger....

Er., to the charger... (with the charger being in vehicle of course.)

[dpeilow]

Does the Tattler allow you to set any current with a granularity of 1A?

19A would be a useful number over here, for example.

[doug]

Does the Tattler allow you to set any current with a granularity of 1A?

I asked that question before and the answer is yes. As to why Tesla doesn't allow that level of control (say with a deeper advanced user screen) is still an open question.

[S-2000 Roadster]

That would be hard to change. Everyone talks about 100 percent. Asking the world to all change to 80% is not likely.

That's fine with me, but the confusing thing is that the Tesla Roadster display shows the actual current, which is less than or equal to 80% of the rated current. So, I'm really just suggesting that Tesla educate their owners on the fact that they'll never get 100% because (U.S.) code never allows 100%.