Trying to get ahead of delivery -- home charger questions

[Frank W]

I bet you the WIFI feature is to enable you to monitor and control the charge times on your vehicle. In addition to being very cool looking I bet you it will be very reliable. I recently had a Jukebox installed to charge my current PHEV; it also has a WIFI connection. So far, I have been very happy with it but, it thinks it is located in the wrong time zone. For some reason, it shows all times in PST and not EST. I may have to redo the setup procedures more slowly and look for the configuration option associated with time zones.

Perhaps some of the current EV owners could weigh in on this. Would the WiFi have anything to do with the vehicles software updates?

 

[ajdelange]

In the previous versions of the HPWC scheduling and monitoring were handled by the car and the car communicated with the charger via the communication wire pair in the cable. What was going on was reported to the driver via the car's network connection. (WiFi if present or LTE). The car would (through the communication wires) tell the charger what it was capable of and what the driver had requested (e.g. my X is capable of 72 amps but i often only ask fo 20). If the circuit has the requested amps available it would give the car permission to draw the requested amount. If not, the car would be given permission to draw what ever capacity were available to keep the total load below the maximum the circuit was set for. For example, an HPWC connected to a 100 A circuit would have its its dial set at D for 80A output and any Tesla built to date would be able to draw its maximum. Were that same charger wired to a 60 A breaker its dial would be set to 9 for 48 A maximum and that is the most any car would be able to get from it irrespective of how much it asked for. Now if in that latter case more HPWC were installed on that same breaker, their dials would be set for F (Slave mode) and an additional pair of wires for communication between them and the Master HPWC. If a second car plugs into a Slave set for 48 A the Slave will send a message to the Master requesting 48 A. If there is a car connected to the Master drawing 48 A there is no reserve on this 48 A max load circuit and the Master communicates to the Slave that no current is available to it. If the operator of the first car reduces the charging current to 30 A there are then 18 A available to the second car, that is communicated to the Slave HPWC and hence to the car which then starts charging at 18 A. When the first car completes charging the whole 48 A is available to the Slave and the second car can charge at 48 A.

The new HPWC are capable of 48 A at most and can thus be installed on breakers up to 60 A. The inter HPWC communication pair is gone as is the dial. The WiFi is there to assume the functions formerly taken by the dial and that pair. One configures an HPWC using a page served out by the HPWC on its own network. It isn't clear how sharing will be configured as sharing is not available at this time but the algorithm will be the same (or very similar) with the communications handled by "unit to unit WiFi". I expect driver control, scheduling and monitoring will be, as before, from the vehicle through the vehicle app.

The HPWCs will connect to your local WiFi network and can be addressed by the Mother Ship for things like firmware updates and this implies that other things could be done with respect to informing the user etc. But there really isn't much value in that as it is already handled pretty well by the cars.

I expect OTA updates will continue to be supported as they are today i.e. through the car's connection to the home WiFI network.

 

[ajdelange]

I had my wall charger installed .... I will have an additional wall charger installed ...

To help people understand how this all works it may be a good idea to remind them that these boxes are not chargers. They are EVSE - Electric Vehicle Supply Equipment whose function is to interface the vehicle to the building's electrical supply system. The actual charger is in the car. It's function is to convert the low voltage AC from the house to high voltage DC. With DC fast chargers the high voltage DC is present at the station. The charger in the car is thus not needed when DC fast charging is used.

EVSE has some safety devices but is essentially a relay (contactor) that connects the charger in the car to the mains. The boxes may contain other circuitry for functions such as current and voltage measurement, WiFi circuits for communication, timers, alarms, logging. etc. The Telsa EVSE for residential use are unique (AFAIK) in that they can manage sharing between multiple units at a location. I believe there are EVSE offered by other manufacturers that permit this plus manage billing, keep logs etc.. Telsa's Level II commercial solution has always been the HPWC. It is pretty clear from the Gen 3 manual that it is designed to be used in commercial as well as residential settings. Perhaps the WiFi connection to the internet will make logging, billing etc. available to the business user.