Octopus Dynamic EV Charging without draining my battery

[steveboz]

I'm on the Octopus Intelligent Go tariff which will allocate dynamic slots for charging and only charge at the low EV rate. At night in the off-peak period I set my solar battery to charge from the grid and when the car is also charging in this period this works fine. The problem I have is when EV charging happens during peak periods in a dynamic slot, it will drain my battery very quickly when I actually want it to come from the grid. I can't set the battery to charge at these times as the are dynamically allocated.

I've found a number of articles/posts/videos online that suggest I need separate the house/solar feed from the EV feed and then the solar CT clamp can be moved on the house/solar feed and not include the EV feed and this will stop the EV charging from the solar battery.

My question is therefore, will this arrangement work with the FOX inverter and battery, or is there anything else that might be needed or considered. I don't want to pay for the re-wiring in my meter box without being confident this will resolve my issue.

[Will]

Hi,

You have two good options.

1. Have your ev charger rewired as per the attachment, hiding the charger load from the fox system to prevent the fox system from discharging to the car charging load.

2. disable the dynamic charging, In the octopus app go to devices, then your device, settings in the top right and disable smart charging. This means your house and car get the cheap slots from 23:30 - 05:30 only with no dynamic charging slots and you can then set your car/charger and fox system to match the charging window.

[steveboz]

Thanks Will for the quick reply and the options. I can't seem to switch off dynamic charging in the App as it gives me an error, not sure if it's automatically tied to the Tariff. Thanks though, I'll reach out to Octopus if I decide to opt for that option.

[CDubbs]

Another new user of solar here, been installed for a week.
My setup is as per the diagram, except clamp difference on Zappi and Solar positions, with my Zappi charger CU wired off a Henley block and it’s CT clamp on the live cable that’s between the DNO fuse and the smart meter, arrow facing into the property.
The FOX CU is also wired into the Henley block as is the house CU.
The Fox CT clamp is on the live cable between the smart meter and the Henley block, arrow facing towards the grid,
I also installed another CT clamp off a Harvi, that sits between the Solar CU and the Henley block, arrow facing towards the Henley block.
On Octopus Intelligent Go
Fox battery is set to draw from the grid between 0000 and 0528, so house load in that period is grid supplied.
Everything works fine, except when Octopus set a charge schedule outside of the above battery schedule, it immediately draws all power from the house battery until it depletes to min SOC (20%).
Plugging the car in when there is excess solar above 1.4Kw min charge on Zappi, works perfectly, flips in and out dependant on excess solar and never draws from house battery, which operates as per design, ie house load, then recharge battery then once full any excess to grid, or car if plugged in.
It’s currently with Myenergi tech support to try to understand what the root cause is.
So in the mean time I’ve decoupled the charger from Octopus, and the car either charges from excess solar as above or now from the grid in the window I’ve set on the Zappi 0000-0500.
16 x 450 watt panels
1 x EP 11 10kw
6kw inverter H1/AC1

[Dave Foster]

Can you take a picture of your meter cupboard showing the cables, henley block etc.. - from what you have said the inverter CT clamp is in the wrong place (with an EV charger) where the Henley block splits the power to go to the EV and the House/Inverter it should be on the House/Inverter live cable.

[CDubbs]

Thanks Dave, Myenergi have just come back with the same observation. Thats where the solar sparky placed it.
I will move and try to see what happens.
Will I lose any functionality on re fox app ?
Any issue having the 2 clamps on the same section of cable ? They can be separated by a couple of foot.

[Dave Foster]

Yes that's in the wrong place it will see all load wired there.

It's not entirely clear from the image as to where all the henley block connections go, the important thing is that the Fox CT clamp must see both the house load and the inverter feed when clipped to a single cable.

If the house/inverter are being joined at that larger henley block you will need to get them to install a small henley block that connects the 2 live feeds together with a single core to connect to the other henley block and the Fox CT clipped here.

[CDubbs]

Thanks Dave, I did realise it was seeing all load in that position.
The 3 CUs are all connected to that one Henley block.
So placing the clamp on the other side of the Henley to Inverter CU will only see load from inverter and no house load, so agree it needs another Henley in the position you describe.
Many thanks for the feedback and support.

[CDubbs]

Thanks for advice Dave, put this to my install company and they are happy to come back next week and install a Henley as above layout for gratis
Thanks again

[Dave Foster]

No problem, great result