Feature Request: Charging Multiple Tesla's Simultaneously

K-MTG · Feb 8, 2016

For many on the forum, the Model X will be their second Tesla vehicle or they plan on purchasing another Tesla in the near future. Unfortunately, most homes aren't built to handle the excessive energy needs associated with charging multiple Tesla's and if possible, the cost associated for an upgraded service is not feasible.

I currently have a Model X ordered and plan on purchasing the Model S & 3. I have a 200 AMP service from SCE, at 80% load the max I can pull is 160 AMPS. As you know, the AMPS can already be adjusted using the Tesla and other 3rd party apps.

I have a Eagle Energy Gateway that reports my live energy usage and integrates with my Home Automation System:

Wouldn't it be beneficial to integrate this with Tesla so AMPS can automatically be adjusted based on the available energy. For instance, I can put a 35 kWh limit so my Teslas' automatically lower the amperage and when one finished charging, the other can automatically amperage increase saving time.

What do you think? Do you think we can develop this?

calisnow · Feb 8, 2016

Until you posted this message I assumed that if you plugged two Teslas into one 200 amp circuit that somehow the load would be adjusted between the cars until they were both charged - how is it done now?

K-MTG · Feb 8, 2016

calisnow said:
Until you posted this message I assumed that if you plugged two Teslas into one 200 amp circuit that somehow the load would be adjusted between the cars until they were both charged - how is it done now?

The loads do not automatically adjust currently, (Tesla's do not communicate with each other) they can only be dialed down manually using the 17 inch display or the mobile app.

eloder · Feb 8, 2016

Sounds like a job for IFTTT integration for Tesla, at a minimum

K-MTG · Feb 8, 2016

eloder said:
Sounds like a job for IFTTT integration for Tesla, at a minimum

Is it possible to conduct a unofficial integration, for instance I recall that someone integrated their Tesla with the Amazon dash

TripleJ3EB · Feb 8, 2016

This is a similar concern that I have, that might be able to be solved the same way. My concern is that if I were to lose power while charging, that I do not want it to start charging again when power is restored to the charger because I could be on generator power, and do not want to run my generator to charge my X. I need it to know that it is not on street power and to not charge until street power is restored. (My generator is large enough to run the entire house and has a auto transfer switch).

K-MTG · Feb 8, 2016

TripleJ3EB said:
This is a similar concern that I have, that might be able to be solved the same way. My concern is that if I were to lose power while charging, that I do not want it to start charging again when power is restored to the charger because I could be on generator power, and do not want to run my generator to charge my X. I need it to know that it is not on street power and to not charge until street power is restored. (My generator is large enough to run the entire house and has a auto transfer switch).

For that can't you simply exclude the Tesla circuit from your backup panel so it is only tied to the grid?

jeffreys · Feb 8, 2016

TripleJ3EB: Look into load shedding modules for your transfer switch. I had them installed for the 2 car charger circuits. In theory, my 20 KW automatic standby generator can power the whole house, but the car charger circuits are too much. In practice, I won't be using the steam shower, both AC units, and two electric ovens at the same time (especially since my only oven is gas at the moment). So there should be enough surplus power to charge the car. If that's the case, the car charging circuits will be energized. If not, they get automatically cut off.

eloder · Feb 9, 2016

K-MTG said:
Is it possible to conduct a unofficial integration, for instance I recall that someone integrated their Tesla with the Amazon dash

Oh definitely.

I'm not an expert, but that Dash trick was a pretty neat. When Dash buttons are unassigned they produce a distinct request that routers can pick up with ease, if set to look for it. That guy made a script that then looked for the Dash press, and then sent that information over to the Tesla side (I'm sure someone here has a ton more knowledge on how things can interact with Tesla Remote).

IFTTT is really wonderful for letting different internet-connected devices work with one another. For example, my Amazon Echo has a voice command that'll let me change the temperature in my home. I'm not sure if there would be some sort of IFTTT device that'd help control current amperage.

scaesare · Feb 9, 2016

WK057 in his "home battery power" thread is modifying a HPWC with the goal of being able to intelligently manage power delivery based on his solar production, available battery capacity, etc...

K-MTG · Feb 9, 2016

eloder said:
For example, my Amazon Echo has a voice command that'll let me change the temperature in my home. I'm not sure if there would be some sort of IFTTT device that'd help control current amperage.

Someone actually interstates with the echo recently, I saw a video on YouTube.

- - - Updated - - -

scaesare said:
WK057 in his "home battery power" thread is modifying a HPWC with the goal of being able to intelligently manage power delivery based on his solar production, available battery capacity, etc...

Can you please provide a link to the thread

scaesare · Feb 9, 2016

K-MTG said:
Can you please provide a link to the thread

Enjoy, or beware, as the case may be: Plan: Off grid solar with a Model S battery pack at the heart

ohmman · Feb 9, 2016

K-MTG, if you're using the API (I seem to recall seeing you post on the telemetry thread), you can certainly do this. Use the API to start and stop charging of each vehicle separately. Use the feedback from your Eagle Energy Gateway or whatever else you need (who leaves first, for instance), to schedule and determine the amount of charge needed for each car.

I'd control it from there using the start charging/stop charging calls, and completely remove scheduled charging from the vehicle control. Or just schedule it for later than when your home automation would already charge - that way it provides a failsafe.

I've done the same thing with my pool. I tried using the scheduling mechanisms of the Jandy interface, along with some logic from my HA system, but in the end decided it's just best to control everything with my HA system.

Chris1howell · Feb 9, 2016

There are several similar efforts to this going on in the OpenEVSE community.

At Caltech in Pasadena there are 50+ stations going in, these stations share a pool of available energy and dynamically allocate capacity as needed.

http://www.teslamotorsclub.com/showthread.php/58038-Free-Destination-Charging-50x-L2-80A-Stations-Caltech-Pasadena-CA

The Wattzilla Duo by liquid sky, is a dual 80A charging station based on OpenEVSE it is avaliable with power sharing. The 2 stations share a single 100A circuit and dynamicly adjust power to 2 vehicles.
https://www.wattzilla.com/index.html

gavine · Feb 9, 2016

The Juicebox Pro (or two of them) might handle what you're looking for.

Source: Electric Motor Werks, Inc. - JuiceBoxâ„¢ Pro 40 - 40-Amp Wi-Fi EVSE with 24-foot cable
"

If you have more than one EV,you can set up your two (or more) JuiceBox Pro units to share one electrical line! Say, you have only 60A remaining capacity in your panel but have two Teslas (lucky you!). You can program your JuiceBox Pro units to never exceed 60A combined draw. If only one car is charging, it gets full 60A of current. When the second car shows up, the current gets shared 30A / 30A between the two. When one of the cars finishes charging, the remaining car ramps back to 60A. This allows you to use your panel capacity most effectively, getting your cars charged quickly without worrying about overloads."

K-MTG · Feb 9, 2016

I would rather have direct integration with the Tesla using HPWC, I didn't know tesla had an API? Anything on Github or similar site?

TripleJ3EB · Feb 9, 2016

K-MTG said:
For that can't you simply exclude the Tesla circuit from your backup panel so it is only tied to the grid?

I do not have a separate panel in the house that's not on the generator. This would require major work on my main panel to isolate it.

K-MTG · Feb 9, 2016

I am sure tesla will have to work something out when the powerwall is officially out

TripleJ3EB · Feb 9, 2016

jeffreys said:
TripleJ3EB: Look into load shedding modules for your transfer switch. I had them installed for the 2 car charger circuits. In theory, my 20 KW automatic standby generator can power the whole house, but the car charger circuits are too much. In practice, I won't be using the steam shower, both AC units, and two electric ovens at the same time (especially since my only oven is gas at the moment). So there should be enough surplus power to charge the car. If that's the case, the car charging circuits will be energized. If not, they get automatically cut off.

This is more about my propane supply. As I do not have natural gas in my neighborhood, I am forced to run from propane tanks, and I am worried that charging the car would exhaust my propane supply much quicker than I want.

ohmman · Feb 9, 2016

K-MTG said:
I would rather have direct integration with the Tesla using HPWC, I didn't know tesla had an API? Anything on Github or similar site?

GitHub - hjespers/teslams: Tesla Model S node.js apps and javascript libraries using Teslas HTTP interfaces

Also, this TMC thread is the discussion for it.

Feature Request: Charging Multiple Tesla's Simultaneously

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