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Adjusting charging amps remotely?

reddy

Member
Jan 26, 2013
893
1,178
Amarillo, TX
Is there any way, with the Tesla or any 3rd party app, to modify the charge rate remotely?

Here why I'm asking:

I have solar panels at home. We are in one of those unfortunate areas without Net Metering. This time of year purchasing electricity from Xcel costs about $0.10, and if I produce excess energy then Xcel pays me $0.03 .

So I want to use as much of my own, solar generated, electricity as possible, minimize the purchase from Xcel, and minimize the sales to Xcel.


I'd like to be able to adapt the charge rate to whatever the actual solar production is , so that I use as much locally produced energy as possible, and purchase the minimum amount of electricity from the utility. Right now I have to hop over to the garage and manually adjust the charging amps periodically during the day. If it clouds over, rather than reducing the charge rate I usually just toggle charging off completely, but I'd like to be able to change amps rather than decide only OFF and ON.

Any suggestions ??
 
Dec 19, 2015
892
793
North Dallas, Texas
In the vehicle on the main screen you can schedule a time to start your charge and adjust the AMPs. Unfortunately the Tesl app currently doesn’t allow for adjustments to the AMPS or to schedule charging.
 

Kuhz

Active Member
Oct 25, 2017
1,899
2,061
Mars
One way you can start a charge remotely is to set the limit and then start the charge. For example when you get home with 50% set the charge limit to 60. It’ll charge up to that and stop. Then you can restart the charge anytime by adjusting the limit higher within the app
 

reddy

Member
Jan 26, 2013
893
1,178
Amarillo, TX
Gents, thanks for the replies. Starting and stopping the charging remotely is a great feature.

I'm hoping that someone here knows if the Tesla API can adjust the amps too, and whether any apps can leverage that.

Since Tesla is trying to be an integrated solar company, the absolute best would be if they included functionality to track inverter output, and essentially become a unidirectional Powerwall.

Oh, should have mentioned that I have placed a 'reservation' for Powerwalls, but Tesla has a hard time estimating delivery and installation. At this point they can't even confirm there will be a installation, but that's another discussion entirely.
 

bradjc

Member
Mar 7, 2016
312
163
Melbourne, Australia
Would love this too. I work from home and often adjust charge through the day jumping in and the car to adjust the amps keeping an eye on our solar output. Hate seeing it go back into the grid for a measly few cents when it can mean kms on the road..
 
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LMichel

Member
Sep 29, 2017
171
136
Rochester, NY
Add me to this list as well! I have an 8kW array and 50+kWh battery array. My system is capable of a priority rule set where it first provides for the house, second it tops off the battery bank. Finally, after the first two priorities are met, the residual is sold back. What I would really prefer is; an additional priority where the remaining energy is put into the Model S instead of sold back to the grid. I'm experimenting with a system feature called "Dump Load" that would turn on my 240v/16A charging unit instead of selling back. The trouble with this is that I still want a minimum charge (say, 125 miles worth) as a priority.
I think that I could achieve this if the function(s) were exposed to the REST API. I could then have the Python script start out with a high charge rate for the car with a charge level (SoC) of about 50%, then stop charging. Later, if conditions are right - I could have an automated API-call change the SoC level to something like 80% and ramp the amps back up.
It doesn't look like the wall connector charging protocol has any control over the SoC, but the Model S does. The car also has the ability to control how many amps it draws. It's just not exposed to the API .....yet.. But if it was, I'd be in business! :)
 
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reddy

Member
Jan 26, 2013
893
1,178
Amarillo, TX
Add me to this list as well! I have an 8kW array and 50+kWh battery array. My system is capable of a priority rule set where it first provides for the house, second it tops off the battery bank. Finally, after the first two priorities are met, the residual is sold back. What I would really prefer is; an additional priority where the remaining energy is put into the Model S instead of sold back to the grid. I'm experimenting with a system feature called "Dump Load" that would turn on my 240v/16A charging unit instead of selling back. The trouble with this is that I still want a minimum charge (say, 125 miles worth) as a priority.
I think that I could achieve this if the function(s) were exposed to the REST API. I could then have the Python script start out with a high charge rate for the car with a charge level (SoC) of about 50%, then stop charging. Later, if conditions are right - I could have an automated API-call change the SoC level to something like 80% and ramp the amps back up.
It doesn't look like the wall connector charging protocol has any control over the SoC, but the Model S does. The car also has the ability to control how many amps it draws. It's just not exposed to the API .....yet.. But if it was, I'd be in business! :)

This is EXACTLY what I was thinking. Sounds like you, BradJC , and I are all asking for the same functionality.

Since there is some interest in it, how does one make suggestions to the Tesla programming team that there is an unmet need here, that could be easily fixed with some code??
 
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kvandivo

Member
Sep 11, 2017
184
222
Downstate Illinois
if you've got all that other glue already there, couldn't you use the data from the car and just charge at max speed for a certain period of time to suck down the extra? I just got my car a couple of weeks ago and don't have anything sophisticated going like you do but here's what I'm envisioning.. TeslaFi shows that we get the current range/battery state, etc. And, TeslaFi shows that we can set the charge percentage.

When the house has been provided for, the battery bank has been topped off, and you are getting ready to start selling, check if the car conditions warrants car charging and, if so, set the charge percentage to "something higher than the charge currently is". This should start the car charging presumably taking from the battery banks. When the two preconditions are no longer met (ie., the house isn't being provided for and/or the battery bank has dropped below a reasonable level (90%?), set the charge percentage to "something lower than the charge currently is" and my assumption is that charging would stop.

This wouldn't be as fine grained as being able to adjust the amps, but should work in a pinch.

Now, everyone can feel free to chime and tell me how much I don't understand how this works. :)
 

reddy

Member
Jan 26, 2013
893
1,178
Amarillo, TX
if you've got all that other glue already there, couldn't you use the data from the car and just charge at max speed for a certain period of time to suck down the extra? :)

It's a bit more complicated kvandivo. I am not in a net metering location. I produce enough electricity to power my car 100%.

If I follow your advice, I will be buying electricity from Xcel from 8am to 10am at 10c/kwh, selling them electricity from 10am - 2am at 3c/kwh, then buying it back from 2pm to 5pm at 10c/kwh.

It's all about synchronizing the charge rate to my excess production, and not selling my excess production for 3 cents when I am later purchasing it back for 10 cents.

Can you verify that you can REALLY change your charge amp rate? I looked at all the 3rd party apps, (Remote S is my current favorite), but none allowed amp changes.

If TeslaFi really does that, then that answers my question!
 

gork

Member
Jan 8, 2018
31
44
Amarillo, TX
Hello, All. I am a new car owner and was looking into this same issue because I would like to be able to automatically reduce the charge rate based on overall panel load. In my case I would like to be able to charge at or near full 80A without having to worry about the state of other high draw devices such as ovens, clothes dryer, etc. on a 125 or 150A panel. This could be accomplished by actively limiting the charge current to a point which leaves 30-50A of overhead on the main breaker.

It looks like TWCManager is already successful at limiting the charge current delivered by the TWC. This program supports adjusting the limit from some outside data; in my case this would be a current meter, but there is no reason that the program could not also query and control the charge state and limits via the Tesla API to support a more advanced ruleset. All the pieces are there to put this together today without Tesla's assistance; it just requires a little software work.

As far as the question of supporting setting limits through the API, I do not think it likely that it will be supported. IIRC the cars themselves have always had the ability to set a charge current limit but did not always have the ability to specify an exact charge capacity limit; the fact that the latter was added to the apps and API without the former strikes me as purposeful. The simplest explanation is probably that requiring the limit be set locally means that most problems due to overcurrent (tripped breakers, fire hazards) are more likely to occur when someone is nearby. An even simpler explanation is that it doesn't fit their Powerwall+Solar narrative.
 

reddy

Member
Jan 26, 2013
893
1,178
Amarillo, TX
I signed up for the free trial on TeslaFi. It's a nice program.

It doesn't allow you to change the chart rate. Like all the others, it allows you to set the target percentage of battery capacity to stop charging..

Perhaps I just need to tweet Elon and ask for this feature.
 

reddy

Member
Jan 26, 2013
893
1,178
Amarillo, TX
OK, I sent the following Tweet to Elon. Let's see if he replies:

"Is there a reason app can't adjust the charge rate on Model S? I have solar, but not net metering. Would be great if my car was a unidirectional Powerwall and tracked solar output somehow. Right now all we have is ON or OFF charging, can't throttle the amps remotely."
 

dave4444

Member
Aug 12, 2017
72
95
NH USA
Certanly doable with an OpenEVSE. Some people have interconnected solar output monitoring to modify the max current on an OpenEVSE.
 

bonu

New Member
Mar 30, 2018
1
0
Lucerne
OK, I sent the following Tweet to Elon. Let's see if he replies:

"Is there a reason app can't adjust the charge rate on Model S? I have solar, but not net metering. Would be great if my car was a unidirectional Powerwall and tracked solar output somehow. Right now all we have is ON or OFF charging, can't throttle the amps remotely."
Great, thx for trying. - Did you get an answer? It would be an easy automation step, if we could change the Amps remotely.
 

BerTX

Supporting Member
May 2, 2014
3,505
3,559
Texas/Washington
The API simply does not contain calls to allow changing the charge rate remotely. There is no method available to developers outside of Tesla to do this. You will not find any app that can magically do it, not even TeslaFI.

You can change the output of the Wall Connector, but currently it is a pretty geeky solution and definitely nowhere near Plug and Play. Even using this solution does not automatically set the charge rate according to your excess solar production, but would allow some manual remote resetting according to current production.

For me, the amount of savings is not worth the trouble. When somebody will sell me a device I can connect to the WC to control it, I'll buy one. I won't build one.
 

LMichel

Member
Sep 29, 2017
171
136
Rochester, NY
Even as I type this; My array has charged the battery bank in my basement and I would like to start pushing amps to the Model S instead of the grid. Why not give me a few more miles and *then* switch to selling the excess..?
When this scenario happens, I can use the API to start charging, however the load will be too much, and the battery bank in the basement will drop below the "re-bulk" level in about an hour.
If I could use an API to say "don't flip to grid, turn the level 2 charger on instead and set charging amps to 'n' times the number of hours of daylight left" - THAT would be awesome!
Have to agree though.. I'm an edge-case at best and there are plenty of other priorities.
BUT, I'm starting to sense app potential here :)
 
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dailo

Member
Jul 22, 2017
635
784
Bay Area
I just set my amps lower and schedule it to start charging around when my system will be close to its peak. Would be nice if I could adjust the amps based on how much excess power I am generating, but haven't found a solution for that yet.
 
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