EVSE Control charge rate

Home Energy Systems
36

@ben I could be interested, but can you explain exactly what is does?

37

Can people share what I need to do to use the EVSE Car charger to slow charge from my PV (obviously when we have longer days).

Is it easy to set up ?

Thanks in advance.

38

You need to send an MQTT message to adjust the charge current. @ben can hopefully shed some light to what the details are on this, he did mine in response to this thread: EVSE Control charge rate - #4 by ben

39

Yes. You need to send a float value corresponding to the grid feed to a specific topic on the MQTT broker on the HEMS (or whatever you want depending on what you are trying to achieve but most people will want the grid feed so that the charger can mop up excess solar). You can set this topic to whatever you want from the EV charger side. There are instructions on the emonEVSE website (although these are aimed at people using an emonPi):

40

@Oscar_Scott do you have a emonPi already?

41

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!

42

Emonpi? Not sure what that is

43

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.

44

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.

1 Like
45

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

46

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.

47

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

48

Hi Ben, could I get one also? Thanks

1 Like
49

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

1 Like
50

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

51

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?

52

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?

53

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.

54

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

55

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.