Thanks, I don't see anything for adjusting the amperage. I only see the ability to start/stop charging so I assume when the first tesla finishes charging the 2nd tesla will start?
I am no expert in programming and have just basic knowledge
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Thanks, I don't see anything for adjusting the amperage. I only see the ability to start/stop charging so I assume when the first tesla finishes charging the 2nd tesla will start?
I am no expert in programming and have just basic knowledge
Right, that's the way I plan to do it. You're correct; currently (!) there's no way to adjust amperage. My way will be to charge the vehicle off of my 14-50 first, then when it's complete, start charging on my HPWC. I don't know what you're using for your HA system, but I'm assuming you can pull it all together there.
I have the SmartThing's HA, it's nothing fancy just a simple consumer home automation HUB. It could be possible by creating a smartapp for tesla intergration since they have an open API.
However, I also have a Mac Mini Server. I would assume it would be easier to create an intergration on the Mac mini using Automator or similar software. I will mess around with the code but let me know if you get it working. Maybe we can create a github project and we can all help each other with the intergration.
Regarding the guy who created the Amazon Dash intergration, is he on the forum? If not, is it possible to contact him?
I suggest you take a peek at Indigo for Mac. I run it on my Mini, and it's really extensible. I have the teslams project (that I linked above) dumping into a MongoDB. Then I wrote a quick python script to populate Indigo variables with those values every minute or so. That way, I can trigger behaviors in my HA system off of that. Indigo also has a Smartthings plugin for interoperability, IIRC.
I have all the mechanics working in python... I also have a Rainforest Eagle Gateway reading my main meter.
Pull data from the Eagle with EAGLE-HTTP-API
Read current draw from 2x OpenEVSE Charging stations via WiFi
Send OpenEVSE RAPI commands via WiFi to dynamicly change pilot
It is not possible to alter the pilot of the Tesla HPWC however you may be able to use python to send commands to the vehicle instead.
Pull data from the Eagle with EAGLE-HTTP-API
Read current draw from 2x OpenEVSE Charging stations via WiFi
Send OpenEVSE RAPI commands via WiFi to dynamicly change pilot
It is not possible to alter the pilot of the Tesla HPWC however you may be able to use python to send commands to the vehicle instead.
It's not clear to me after reading the Wattzilla Duo technical details that it can dynamically balance. There is an optional feature- Wattzilla - Dual 80 amp EV charging station called powershare that hints at it, but they don't go into detail on how it works.
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While this works, I suspect to meet code, the powers that be will want the EVSE to change the pilot signal.
How did you pull data from the eagle?
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I am definitely interested in hearing more about your Tesla setup with Indigo. I will purchase Indigo this weekend and mess with it
The Wattzilla Powershare uses a single 100A circuit to share between 2 80A outputs. The 2 controllers internally are tied together with a serial link to coordinate current allocation and report back usage. Liquid Sky certified their products through UL with the OpenEVSE RAPI communication protocol enabled so external control is possible.
Yes, to meet code, the charging station will have to control the pilot. J1772 includes dynamic pilot in the spec. Using the Tesla REST protocol is useful but likely not reliable or quick enough to be used for a real time applications.
Any tutorial for installing the terminal integration: GitHub - hjespers/teslams: Tesla Model S node.js apps and javascript libraries using Teslas HTTP interfaces
From the screenshots it appears they got it to work on terminal, any software recommendation for compiling?
I am a newbie to programming, I only know a little bit of C, C++, and python. I don't know any java script.
Help would be appreciated, Thanks!
From the screenshots it appears they got it to work on terminal, any software recommendation for compiling?
I am a newbie to programming, I only know a little bit of C, C++, and python. I don't know any java script.
Help would be appreciated, Thanks!
And what criteria does it use to decide the split? If only one car, 80A. If two cars, 40/40 until one stops charging? Or 80A on one until it's done, then 80A on the second?
Current allocation starts out at 50%/50% but is continuously measured and reallocated as current is available.
For example a Volt capable of 16A and a Tesla with twin chargers....
First Vehicle to plug in - would get 80A.
Second vehicle plugs in - would change pilots to 40A/40A.
After current is measured pilot signals would end up with a split of roughly 18A/62A. As a vehicles load tapers down the current is reallocated to the other.
When the first vehicle finishes charging the 2nd gets all 80A.
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It looks like the hjespers/teslams does not have a method to reduce charging current so I do not think it will work.
I have been logging the data from my Eagle Gateway on the OpenEVSE Energy Monitoring Portal. The Graph Below depicts total usage and production (5.8kw Solar) from the main panel via the Eagle Gateway with a Tesla Charging at ~6kw and a Leaf Charging at 1.44kw.
It should be not be too difficult (with OpenEVSE) to add a maximum peak load and dynamically control the charging stations.
I'm know I'm not telling you anything you don't already know, but ... Teslas don't taper with AC charging until the very, very end. What I don't know is, do are Teslas ok with the pilot signal changing multiple times (up and down) during a single charge? If you set a dual-charger S to 80A, and the pilot goes from 80 to 40 and then back to 80, will the Tesla ramp down and back up? If so, I wish I had discovered this option as I'm just completing an install of two HPWCs at 80A to give me the charging rate I need for my TOU plan with two cars (and S and X). However, I doubt they would both need all 4 hours (my ultra-low window) at 72/80A (X and an S) on the same night to fully charge. It will happen, but it will be rare.
The SAE J1772 specification requires vehicles to respond to a pilot change within 5 seconds.
A while back I did an experiment to dynamically change the charge rate based on the output of a solar array. The Model S responded appropriately to pilot changes. At a below 1.2Kw Production OpenEVSE would go sleep.
Here is another example...
OpenEVSE has a Temperature Monitoring and Throttling feature, if the internal temperature of the charging station gets too hot the charge rate is reduced. If the temperature continues to rise the charge rate will drop several times before completely shutting down. Here is a graph that includes a couple temperature events on a very hot August Night in the Mojave desert (over 100 in the garage). The pilot goes down and back up and the Tesla responds perfectly.
Darryl
ModelXTracker.com Co-Adm
With the cost of the Wattzilla it would probably be less expensive to have your main service increased and add a dedicated 200 amp panel and two dedicated 100 amp circuits. Don't forget part of this may be a tax deduction under [COLOR=rgb(1.960000%, 38.800000%, 75.700000%)]Fixing America’s Surface Transportation [/COLOR](FAST) Act.
Ulmo
Active Member
This is fantastic.
This is great.
This is nice.
I'm glad solutions like this are coming out.
What I'm personally looking forward to is an answer regarding a hypothetical EVSE that delivers Direct Current at SuperCharger or Chademo speeds (if available) from either of solar PV panels and/or battery storage, integrated with whatever inverters are there to add, divide and apportion loads appropriately, or if insufficient Direct Current supplies are available at the efficiency point desired, can go to Alternating Current supplies, especially one integrated to a lower cost AC supply time period or opportunity (think windmill power in Texas or EV-A PG&E tariff).
Here's some ideas I think would be part of that, and I would like to hear if any of this is close to reality or if it's just bunk:
- Putting Solar PV panels in series to get high enough voltage to charge a Tesla or other EV using DC and doing so in parallel to get enough Amps would require some type of wiring and load distribution (inverter?) integration. Some solar panel arrays are set up for pretty high voltage DC (over a thousand volts mid-day), whereas others are lower voltage. What considerations does this cause?
- Some battery storage solutions have pretty high voltages, but don't seem to have exactly the right voltage needed to charge a Tesla or other EV in Direct Current. Would these also need to be serialized and parallelized for optimal power?
- Would battery storage and solar panel storage in series allow increased voltage, and could they be managed together to deliver good voltages to charge a Tesla or other EV?
- Can a single EVSE and connector be utilized for some EV's that allow a hybrid of charging types to switch from one to the other as resources allow? Such as using DC when solar panels and/or battery storage have available DC, but switch to AC when not the right type of DC is available?
- Is it more efficient to deliver DC directly to a Tesla or other EV rather than convert a DC source to AC and convert that AC source back to DC? Or is the management provided by the equipment that converts DC->AC->DC useful enough that it is worth the efficiency losses? Is this always the case? Will we expect to see the right power equipment come onto the market in the next half decade to decade as DC power in home power becomes more common?
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