EVSE Control charge rate

Home Energy Systems
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Hi @David_Sawdon & @Oscar_Scott! I hope you don’t mind, but I merged the thread EVSE trickle feed from PV into this existing thread since I think there a major overlap. I hope that is ok!

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Emonpi? Not sure what that is

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Hi Ben, we spoke about this too, I’d like the sensor please and details on how to set the trickle feed up from PV via the EVSE. Thanks.

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Sure ive got a list of people for this. I have more monitors on back order. Will write a documentation page on how to setup but is fairly straightforward.

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Hi Ben,
I would like a sensor as well. I currently monitor using the Powerwall, but tesla keep changing the login system so its not always reliable

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I wondered what had happened to this - I now realise that I didn’t hit send :frowning:
If it’s still something you can send it would be very useful.

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Sorry @Simon_Hudson I think I slipped up here. I sent 2 out previously and thought I was done. I will sort one out.

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Hi Ben, could I get one also? Thanks

1 Like
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You as well! Sorry. Now wondering who i did send them to…

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Thank Ben - I’m pretty sure it was my fault, not yours; I really appreciate it however.

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Hi Peter. I missed this reply in the December strangeness. I now have the EVSE installed on the outside of my home for visitors etc., post PowerShaper phase 1. I’m keen to enable the charge rate function etc., so if you are still able to take a look. What info do you need from me?

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Hi Simon, I’ve been tinkering with it for a while now, so have a pretty good idea of what to do now. What exactly are you wanting to do? follow solar, or just toggle between a few different charge rates?

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A quick update on this, I placed an order for the bits for this last week . Shelly (who make the controllers) stopped selling kit directly to UK (except through resellers) so have had to source them in UK and I think they might have a lead time. Will be chasing up.

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Cheers for that Ben, looking forward to integrating it all together

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After 18 months of using the Octopus Agile and Outgoing tariffs, I have now changed to Octopus Go Faster - 5 hr tariff. From 20:30 hrs till 01:30 hrs I am charged 5.5p per kWh and for the rest of the 24 hr period I’m charged 15.96 per kWh. Both include VAT. The Standing Charge has gone up from 20 to 25p per day and the Outgoing rate has gone down to the Smart Export Guarantee a fixed 3p per kWh.

Octopus Agile half hour tariff rates have been going up for the last 4-5 months, but the crunch came last Thursday 15 July 21 when I needed to put extra charge into my EV. The cheapest half-hour Agile price was 15.98p kWh - higher than the fixed Octopus Go Faster Rate of 15.96p kWh for 19 hrs per day - if I could not charge with the 5 hr slot at 5.5p kWh. Agile prices are continuing to rise. Cheapest half hour slot today 21 July 21 - 17.09p kWh and tomorrow 17.03p.

So I’m experimenting. Rather than buy cheap and sell (export) when more expensive - that requires a lot of manual effort to select the half hour slots, I simply going to buy when cheap (5.5p kWh). As I already have a 15 kW Home battery storage system plus two solar PV arrays totally 3.8 kWp - it should be possible to power the house and the EV with electricity that is free (solar) or buy cheap electricity at 5.5p and rarely, if at all, need to buy electricity at 15.96p. It should also be easier to schedule - once I have it set up.

If Agile prices go down or it is not working out cheaper I can always go back to Agile after 30 days.

But, that is where I need help from @ben or anyone else. I’m sure its easy to do, but perhaps its the hot weather, I can’t figure it out how to do it in Home Assistant. I think I will need a Scheduler Card that will enable me to select multiple time periods (up to 10) when I want to switch on the EV charger to charge and then switch off. Can anyone help?

Once set up, I can fine turn it and in conjunction with my Solar PV using a different App, try to ensure that the Home Battery storage does not go below 30% charged or more than 100% - when it starts exporting to the Grid. Note when I charge my EV it will draw from the Home Battery Storage system first before the Grid.

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Hi Peter, have you managed to create any automations in Home assistant yet? This is where you can setup the EVSE to turn on at night, or during times of excess solar generation.

I have the exact same setup as you have described, along with the Go tariff, and my system is setup like this, so I don’t have to do anything manually

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@Peter i am sorry i missed this. As it is just fixed times of day i would use the automations as @Oscar_Scott suggests instead of that scheduler card. I will try to create an example of this on yours today.

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Thanks @Oscar_Scott I have been using automations for Octopus Agile previously. Thanks @ben Look forward to you setting it up. The key thing is that when I charge up the EV it first takes up to 5kWh from the Home battery storage system plus the remainder from the Grid. But I don’t to to discharge the Home battery storage system below 30-35% by 01:30 hrs - so that the home grid draws power from without going down to 10%. If it reaches 10% it starts taking electricity from the Grid at peak rate.

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So my Go period is between 21:30 - 1:30.

My automations are as follows:

  1. If Powerwall % is above 90%, and time is between 7:00 and 21:30, then turn on EVSE at 13A (3kW).
  2. If Powerwall % drops below 75%, and time is between 7:00 and 21:30, and EVSE is on, then turn EVSE off.
  3. At 21:30, turn on EVSE at 32A (full power)
  4. At 1:30 turn off EVSE
  5. At 00:30 if powerwall % is below 30%, set powerwall to backup only mode (charges from grid)
  6. At 23:30 if tomorrows weather does not call for sun, set powerwall to backup only mode
  7. between 23:30 and 1:30 if the powerwall % goes above 60%, set to self powered (house runs from powerwall)
  8. at 1:30 set powerwall to self powered.

1 and 2 send excess solar power to the car. I have chosen 3kW as my solar output averages that, so in theory the powerwall % hovers around 90% once the first automation triggers.

3 and 4 set the charger on during my Go period at full power

5 -8 manage the powerwall state of charge during the go period, to draw from the grid if necessary, and to cover the nighttime until the sun rises.

Hope this might help

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Thanks @Oscar_Scott Yes these are virtually all the automations that I would like to have. Some of the actions I’m currently doing manually. Questions:-

  1. Are you able to control your home battery system (Powerwall) through the HEMS/HA? I can’t do this at present @ben has started to look into it - but as yet does not have a solution. My battery is a Soltaro system (Australian company - with Chinese connections that are not totally clear) Currently, I can do forced charged and forced discharges from the Soltaro battery using an Android App that should only be used by installers and only when it connects to my home Wifi.
  2. How do you turn on EVSE at 13A (3kW)? Are you using a smart plug like a tado or Teckin that communicates to the HEMS/HA?
  3. I assume you will have to physically (manually) have to unplug cabling for EVSE at 13A (3kW) and replace it with a different Charging Cable for the EVSE at 32A? (my Nissan Leaf only has one socket for charging with both types of cable.
  4. @ben is going to upgrade my version of HEMS and then it will be possible to install the Forecast.Solar integration
  5. I’m not entirely sure what you mean by “set to self powered (house runs from powerwall)”? My house (and EV) always run from the Home battery Storage first and then directly pull from the grid if the home load is greater than 5kW. This was the default set when the home battery storage system was installed.