apostolakisl Posted June 14, 2022 Posted June 14, 2022 My new Tesla is finally arriving next week after a 6 month wait. This is my first Tesla. I was looking at charging at the office where I am on a kw + kwh billing system. In other words, your worst 15 minutes of wattage during the month determines about 2/3 of the bill and kwh is only ~5c each. So, my thought was, to only let the Tesla charge when my wattage was low so it only cost me 5 cents/kwh and doesn't bump up my high watt level. It sounds like this node could help. Basically, I would like to tell the car to charge whenever certain conditions are met. Either I monitor my overall power usage, or just monitor the big draw items, like AC units, and only charge when they are idle. Anyone have thoughts on this?
Panda88 Posted June 14, 2022 Posted June 14, 2022 Congrats on the car, I think this should work - you can specify max charge current - but you need to make sure it works correctly - I have not been able to verify it You have to be a little careful as there is (I believe) a delay from the tesla API - I htink commands are ok but getting data back may have some delay
apostolakisl Posted June 14, 2022 Author Posted June 14, 2022 9 minutes ago, Panda88 said: Congrats on the car, I think this should work - you can specify max charge current - but you need to make sure it works correctly - I have not been able to verify it You have to be a little careful as there is (I believe) a delay from the tesla API - I htink commands are ok but getting data back may have some delay It would only matter on command, not response. The max kw is based on a running 15 minute average, so even if there were a short delay of something under a minute, it would not likely affect the 15 minute running average much. I need to figure out the best method for getting the trigger data into ISY. It is 3 phase and Sense, which I use at home, doesn't do 3 phase. So I need to figure out a different way. Right off, I know I could use a webcontrol board and just monitor the AC units with that and only charge when they are idle. Though I might never charge the car the way this summer is going.
stevehoyt Posted June 15, 2022 Posted June 15, 2022 Not to be a debbie downer and I like a good engineering solution as well as anyone else...... A couple data points, after having both a tesla S and 3 for 5 years now. Number 1 you are going to love it. I still have 2 internal combustion vehicles, but can't imagine buying any more. The big key is how many miles you drive each day, freeway or not, and to some extent the weather etc. But as a rule of thumb you can expect to get about 3 to 4 miles per KW. So if you drive 60 miles a day, you might need to add 15 - 20 kw per day. You can adjust these numbers for your usage. You can plug it in a normal 110v outlet charging at 1500 w/hour and with losses will get about 3 miles per hour. Not ideal, but my retired neighbors who don't drive much, do just fine charging that way. If you have access to a normal dryer plug you can easily get 5 KW/h or approx 15 to 20 miles per hour. If you want to rewire you can get higher speeds, though most people won't need them. I have a 5KW plug at home. In my case, I do just fine charging for about 5 hours every 2 or 3 days in the middle of the night at off peak. My point being work charging on a KW+ rate may not even be needed. So think about your daily mileage first. The car also will let you program the charging rate based on location. So you could set it to charge slowly at work and faster at home in the middle of the night. You can also set it to charge at a specific time, or be ready at a specific time, and it is aware of TOU rates. Lastly polling the car to set/query status, wakes the car up resulting in KW usage keeping the computers and wifi connections up and talking to the mothership. I have seen it be as high as 2 kw per day when I was querying a lot. Better to let it go into deep sleep. I had range/charge anxiety when I got my first one. In reality charging and range for me are no big deal. Please feel free to ask any questions you want. I already made this far longer than I wanted to. I am sure there are other Tesla owners who might've more to add or comment on my thoughts. 1
apostolakisl Posted June 16, 2022 Author Posted June 16, 2022 1 hour ago, stevehoyt said: Not to be a debbie downer and I like a good engineering solution as well as anyone else...... A couple data points, after having both a tesla S and 3 for 5 years now. Number 1 you are going to love it. I still have 2 internal combustion vehicles, but can't imagine buying any more. The big key is how many miles you drive each day, freeway or not, and to some extent the weather etc. But as a rule of thumb you can expect to get about 3 to 4 miles per KW. So if you drive 60 miles a day, you might need to add 15 - 20 kw per day. You can adjust these numbers for your usage. You can plug it in a normal 110v outlet charging at 1500 w/hour and with losses will get about 3 miles per hour. Not ideal, but my retired neighbors who don't drive much, do just fine charging that way. If you have access to a normal dryer plug you can easily get 5 KW/h or approx 15 to 20 miles per hour. If you want to rewire you can get higher speeds, though most people won't need them. I have a 5KW plug at home. In my case, I do just fine charging for about 5 hours every 2 or 3 days in the middle of the night at off peak. My point being work charging on a KW+ rate may not even be needed. So think about your daily mileage first. The car also will let you program the charging rate based on location. So you could set it to charge slowly at work and faster at home in the middle of the night. You can also set it to charge at a specific time, or be ready at a specific time, and it is aware of TOU rates. Lastly polling the car to set/query status, wakes the car up resulting in KW usage keeping the computers and wifi connections up and talking to the mothership. I have seen it be as high as 2 kw per day when I was querying a lot. Better to let it go into deep sleep. I had range/charge anxiety when I got my first one. In reality charging and range for me are no big deal. Please feel free to ask any questions you want. I already made this far longer than I wanted to. I am sure there are other Tesla owners who might've more to add or comment on my thoughts. Thanks for the info. Directly in front of my parking spot at the office are my AC units. When I bought the space, I re-did the AC and went from 4 units to 3 units. So I already have a 50 amp circuit just sitting there doing nothing. I don't actually drive that many miles. My current car is a CTS-V, is 11 year old and only has 65,000 miles on it. We have largely used my wife's car for the bulk of driving, but perhaps that will change after I get this car. Back in the day I thought 558 hp was impressive. Now it is 1000+hp or I'm going home. Anyway, I have always loved the wolf in sheep clothing car. . . the 4 day family sedan that kicks ***. Probably talking about a few bucks/month, but whatever, I have to charge it somewhere and being a HA junkie, I just want to do it. The cost of the car itself dwarfs the cost of the electricity, so it is kind of joke, but again, whatever. Basically, I just need the node server to give me control of the charging. To tell the car to start and stop charging. Not sure if you have to keep the car awake to do that. Doesn't seem like keeping the computers in the car on should have much power draw, but what do I know, I don't yet own it.
stevehoyt Posted June 16, 2022 Posted June 16, 2022 I will be interested to hear your impression after you have had it awhile. Here is another way to do what you want via load shedding on one AC. This one is not outdoor rated and not sure if hardwiring an AC to it is code, but you get the idea. If you search the internet there might be one that would work outdoors and allow hardwiring. Just a thought. https://www.getneocharge.com/smart-splitter Also if you are willing to pay 5 $ a month and allow a developer to see your cars data, I use Teslafi. More info than you will ever need to know. Screen shot below. 1
apostolakisl Posted June 16, 2022 Author Posted June 16, 2022 @stevehoytThat smart splitter looks easy, but for $500 I think I could do it for free. I already have CAI webcontrol boards which I can hook up to my AC units to know when they are running and I can do that in the attic. At that point, assuming the node server can tell the car to charge or pause charging, I just need to write a program on ISY. I haven't seen the node server working yet since it seems as though I actually have to have the car before the nodes will install. So, I'm not 100% that the node server can start/stop charging. Can you confirm that the node server can do that?
stevehoyt Posted June 17, 2022 Posted June 17, 2022 sorry I can't I am not using the Node server currently.
apostolakisl Posted July 19, 2022 Author Posted July 19, 2022 Not sure I can use this without some changes. I got my Tesla and then immediately went on vacation. I left the car with 90% charge but did not have it plugged in. About 10 days into my vacation I thought to see how my Tesla was doing. the battery was at 35%! It was losing roughly 5% per day just sitting there. I shut off the node server, and over the next 10 days it might have lost 1 or 2% more. In short, the node server seems to keep the car in a state of energy sucking that is pretty significant.
apostolakisl Posted August 15, 2022 Author Posted August 15, 2022 @Panda88 Just wanted to bump this again. It looks like using the node server keeps the car in a very high state of power usage just sitting there. Can this be fixed? Killing 5kwh/day to use the node server isn't going to work. The Tesla app itself seems to let the car go to sleep.
apostolakisl Posted August 16, 2022 Author Posted August 16, 2022 @Panda88 Is it the polling intervals that is killing the battery? What if I change the polling intervals to really big numbers? By default they are set to 60 and 600. Not sure what short poll is vs long poll. Could I set it to just poll once a day (86400 seconds)?
Panda88 Posted August 17, 2022 Posted August 17, 2022 yes - if you poll often the car never goes to sleep (I am told) - Unfortunately I do not have a Tesla so I cannot experiment Setting the long polling interval to a large number allows the car to sleep - you can wake the car (from the ISY) if you want data updated 1
apostolakisl Posted August 27, 2022 Author Posted August 27, 2022 I seem to have this working thanks to @Panda88 and @bpwwer The Tesla node server, with long poll set to 86400 and short poll set to 86399 (not sure if short poll is needed) lets the car sleep but you can send commands to it or query it when needed. The Emporia Vue node along with the device itself lets you monitor current real-time watt draw. There is a test version of the app that has this functional. Then I wrote a series of programs which seem to be doing the trick. I also have the programs in a folder which is linked to my phone geofence such that the programs only run when I am at the charging location in question. I don't want to have Tesla start and stop charging based on electricity usage at a location where the Tesla is not charging. It seems like a lot of programs, but I couldn't see a way to do it in fewer. I want the car to stop charging if power usage is above 14kw and then to resume when it drops below 9kw. I have the car set to charge at 3kw. I also don't want it to stop charging if there is just a quick spike from say a motor start, so I have a delay of 5 seconds, it checks again and then shuts down the car charger if it is still high wattage. Also, the Emporia Vue wattage is a state value and it updates every 2 seconds, meaning it will trigger an if clause every 2 seconds since the value always changes. So I didn't want the program to send a "start" or "stop" command repeatedly every 2 seconds once it has already started or stopped. Not sure if that would be a problem, but it just seems like a bad idea. Tesla - [ID 005C][Parent 0094] Folder Conditions for 'Tesla' FOLDER RULE If 'GeoFence Office / LouS22' Occupied is True Then Allow the programs in this folder to run. Tesla Charge Start - [ID 0062][Parent 005C][Not Enabled] If 'emporia VUE test' Killowatts < 9.0000 kW Then Run Program 'Tesla Charge Start 2' (Then Path) Else - No Actions - (To add one, press 'Action') Tesla Charge Start 2 - [ID 0066][Parent 005C] If - No Conditions - (To add one, press 'Schedule' or 'Condition') Then Disable Program 'Tesla Charge Start' Set 'Raymond / EV Charging Info' Charging Control Start Enable Program 'Tesla Charge Stop' Else - No Actions - (To add one, press 'Action') Tesla Charge Stop - [ID 0060][Parent 005C] If 'emporia VUE test' Killowatts > 14.0000 kW Then Run Program 'Tesla Charge Stop 2' (Then Path) Else - No Actions - (To add one, press 'Action') Tesla Charge Stop 2 - [ID 0064][Parent 005C] If - No Conditions - (To add one, press 'Schedule' or 'Condition') Then Disable Program 'Tesla Charge Stop' Wait 5 seconds Run Program 'Tesla Charge Stop 3 always disabled' (If) Else - No Actions - (To add one, press 'Action') Tesla Charge Stop 3 always disabled - [ID 00D8][Parent 005C][Not Enabled] If 'emporia VUE test' Killowatts > 14.0000 kW Then Set 'Raymond / EV Charging Info' Charging Control Stop Enable Program 'Tesla Charge Start' Else Enable Program 'Tesla Charge Stop'
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