Octopus IOG, EV Charging and home battery storage

[Pistonheadsdicoverer]

I noticed this morning that my home battery was almost empty and that coincided with the fact that I charged my EV and set the limit at 8am this morning. I use Soliscloud. Does anyone know how I can prevent my battery from discharging into my EV. Or does anyone have any tweaks. I guess going forward I will align my EV charging with the low cost IOG tarfiff (i,e till 5.30).

[paradigital]

No idea about soliscloud, but with my FoxESS system I have a schedule set whereby charging the battery is prioritised over usage. This means that the battery doesn’t discharge at all during the IO cheap rate overnight, even if EV charging, dishwashing, washing machine etc.

Once the cheap rate (05:30) ends, then the inverter/battery schedule changes to prioritise self-consumption, charging the battery and export in that order.



That’s yesterday’s stats and SoC graphs.

I’m planning on playing with HomeAssistant and the FoxESS API to switch the operating mode to prioritise charging the battery if the car gets told to charge by Octopus.

Edited by paradigital on Saturday 20th July 09:05

Edited by paradigital on Saturday 20th July 09:09

[Road2Ruin]

I set my battery to charge to 100% every night between 23.30 and 05.30. While the battery is charging, even if the car is also, the battery does not provide any for the car.

[NugentS]

Thats how I do it as well. Charge Car 23:30 to 05:30, Charge house batteries at that time and don't let them discharge in that time period.

Its a disaster(from a house battery PoV) to allow Octopus to control when the car charges. If they schedule a outside core IOG charge then my house batteries get flattened.

I can see controlling this with something like Home Assistant except I have Luxpower Inverters on the batteries - and there is no acess from HA to luxpower as far as I can tell - [There is one but it doesn't work with the newer dongles which are more secure]

[Road2Ruin]

NugentS said:

Thats how I do it as well. Charge Car 23:30 to 05:30, Charge house batteries at that time and don't let them discharge in that time period.

Its a disaster(from a house battery PoV) to allow Octopus to control when the car charges. If they schedule a outside core IOG charge then my house batteries get flattened.

I can see controlling this with something like Home Assistant except I have Luxpower Inverters on the batteries - and there is no acess from HA to luxpower as far as I can tell - [There is one but it doesn't work with the newer dongles which are more secure]

I am not sure how my electrician has set it up, but the car never charges from my battery. It's an odd one I must admit, and no idea how he did it.

[Blockbuster]

I use SolisCloud. Firstly you need to get Solis to enable remote control.

https://solis-service.solisinverters.com/en/suppor...

Once you have this enabled, you go into

Device > Inverter > (3 dots menu) > control inverter

Accept terms and enter password

Work Mode > Self-use Mode > Charge and Discharge

There’s 3 slots you can set as Charge Times. The battery will top-up from the grid during these times (hopefully during cheap rate) but it will also stop it emptying into the EV.

I have one permanently set to 23:30 to 05:30 but if I ever get some additional IOG slots I add them too. It’s a bit of a faff and one day I’ll look to see if I can set up home assistant to automate it.

Edited by Blockbuster on Sunday 21st July 08:23

[this is my username]

Easiest way is as described above - with IOG I just set the completion time for the car as 05:30 and charge the battery 23:30 to 05:30. If the car starts charging early then it's doing it on cheap rate anyway so the whole house is on cheap rate - so it doesn't matter if the battery goes flat.

What you can do to avoid all this is to move your CT clamps. You need:

The car charger CT clamp on your main feed from the meter - that measure the total house load from the grid and will reduce the draw from the charger if it becomes too high.

Then a henley block supplying the charger.

Then a second henley block with the connections to the solar, battery and consumer unit.

The solar and battery CT clamps go on the link between the two Henley blocks - so they don't see power drawn by the car charger.

By doing that the charger is invisible to the battery, and the battery will only supply the house.

If you google you will find some diagrams online - something like this:

https://www.youtube.com/watch?v=EmxN-gJaGUw

Edited by this is my username on Sunday 21st July 08:44

[Road2Ruin]

this is my username said:

Easiest way is as described above - with IOG I just set the completion time for the car as 05:30 and charge the battery 23:30 to 05:30. If the car starts charging early then it's doing it on cheap rate anyway so the whole house is on cheap rate - so it doesn't matter if the battery goes flat.

What you can do to avoid all this is to move your CT clamps. You need:

The car charger CT clamp on your main feed from the meter - that measure the total house load from the grid and will reduce the draw from the charger if it becomes too high.

Then a henley block supplying the charger.

Then a second henley block with the connections to the solar, battery and consumer unit.

The solar and battery CT clamps go on the link between the two Henley blocks - so they don't see power drawn by the car charger.

By doing that the charger is invisible to the battery, and the battery will only supply the house.

If you google you will find some diagrams online - something like this:

https://www.youtube.com/watch?v=EmxN-gJaGUw

Edited by this is my username on Sunday 21st July 08:44

Must be what my electrician did, as my car never charges from the battery

[ashenfie]

That makes sense to me you don't want the car draining the house battery. The battery is going to be around 5-10kw and the car around 50kw, so it would most like suck the life out of the battery at a very slow charge rate (if you have a 3.5kh inverter). Therefore the battery is meant to provide power to the house only.