Intelligent Octopus Go and Home Batteries

don9999

I have recenlty had my Octopus EV charger installed, and I am registered to Intelligent Octopus Go.  In 'theory' this is great and means that my EV will be charged during the day/night at cheap rates.

HOWEVER....in practice, if Octopus schedules my EV to charge during the day, it simply drains mySigEnergy battery, leaving the battery depleted for later household use 🙁

This is going to COST me money, rather than save me money 🙁

I specifically asked the Octopus installer to install the charger on the GRID side of my SigEnergy inverter, assuming that would mean the battery could not see it and hence would not discharge to it.  However, the battery DOES discharge whenever Octopus decides to charge the EV.

There 'may' be something that can be done with CT clamps, and/or Henley block.  But I am no electrician, and even if/when I understand what might be needed, I couldn't do it myself.  Would I need to get the SigEnergy installer to do it, or the Octopus Charger installer, or any electrician?

At the moment, the only options I have are:
*  Only plug in EV at 11.30pm

*  IF EV is plugged in during the day, and charging starts, to manually configure battery NOT to discharge (indeed, I 'could' set it to charge at low rate)

* Use third paty software like HomeAssistance to manage the battery charge/discharge

The second option is doable in the very short term, but is an extreme pain having to manually monitor/configure on the fly, every day!
The third option is doable in the medium term, but first I have to get access to the Inverter's modbus (not easy requesting permission from the installers), AND I then have to learn how to configure use this third-party app.

Surely I can't be the only/first person in this situation....

What have other people done in this scenario?

Background

I have a SigEnergy system consisting of solar panels, Inverter and 20Kwh batteries.

I have an Octopus EV charger, and a Tesla EV

QrizB

don9999 said:

There 'may' be something that can be done with CT clamps, and/or Henley block.  But I am no electrician, and even if/when I understand what might be needed, I couldn't do it myself.  Would I need to get the SigEnergy installer to do it, or the Octopus Charger installer, or any electrician?

It's easily DIYable, in many cases.

This has been discussed recently - in the past 3 weeks - in @SuzeQStan 's thread here:

https://forums.moneysavingexpert.com/discussion/6647353/new-comms-hub-no-gas-1-2-hourly-readings

Start half-way down the first page and continue to the end.

Can you share some photos or a schematic of your system?

don9999

Thanks QrizB :-)   (I did search forums first but didn't come across that post :-( )

I was about to update MY thread anyway, as after further investigations, I came to the same conclusion!

The issue appears to be that the SigEnergy Grid CT clamp is situated somewhere downstream and is measuring TOTAL import, including the EV charger leg.

The fix appears to be to relocate the Grid CT so it measures only the house feed from the Henley block, 'excluding the EV feed'.

I don't think it was anyone's fault - SigEnergy was installed first, then the EV charger was installed, correctly on the Grid side.  But....this 'system change' resulted in the Grid CT measuring the wrong thing.

I have to believe that this is VERY common with people getting EVs 'after' they already have a solar system installed.  Am quite surprised that this anomaly is not publicised more, and/or that the installers don't mention it at the time of installation so that it could be dealt with up-front rather than left to the consumer to discover the adverse repercussions.

For now, I have to go back to the SigEnergy installers to ask them to relocate their CT clamp.

Cheers,

Don

QrizB

Glad you've found a solution!