BEV charger questions

[Stinsy]

The master plug ones are highly regarded: https://www.screwfix.com/p/masterplug-3 ... e-5m/525kr

[Krill]

Stinsy, I can't find any masterplug 10m cables at Screwfix.

AGT, thanks, that's the best price I've been able to find.

[Ken]

Having a CT clamp on the grid supply and one on the immersion heater and then joining them together before entering the Zappi the immersion heater will charge until such time the measured current at the Zappi reads min 6amps when the Zappi will charge the car and disconnect the immersion and vice versa when clouds or evening. This utilizes all the surplus PV until they are full and then goes on to export or charge the batts.

However this is old thinking because with TOU tariffs i would demand shift EV,HW,HP, batts and others to the cheap rate and export the surplus PV at the 15p. I would not use the batts for arbitage as i consider that poor value after hammering the batts.

Not sure I understand the theory of this. Yes you can add the (signed) current draw of two devices using two CTs but does the control aspect rely on the immersion controller being a Myenergi eddi? Mine is home brewed, needs 50W export to turn on fully so has priority over the zappi (set as per MIs to 100W) but frankly CBA to modify that threshold.

Particularly as am expecting to be moved from deemed export to Octopus Fixed Outgoing when they get round to it, then I will as you say benefit from 15p/kWh and it will be cheaper to heat the immersion at night at 12p than sacrifice exports.

Sorry for very slow reply.
Any diverter will work with the above. Once the Zappi detects 6A + being used by the HW diverter it will switch on and cut off the diverter. When the HW is full the zappi will only switch on if it detects 6A+ being exported at the meter.

But as i said that is old hat -just throw as much demand as possible into 7p/kwh TOU slot and export as much of PV as poss.

[sharpener]

Sorry for very slow reply.
Any diverter will work with the above. Once the Zappi detects 6A + being used by the HW diverter it will switch on and cut off the diverter. When the HW is full the zappi will only switch on if it detects 6A+ being exported at the meter.

But as i said that is old hat -just throw as much demand as possible into 7p/kwh TOU slot and export as much of PV as poss.

That makes sense but as you say is no longer optimal.

Now that the DNO has withdrawn their 3.7kW limit I can export the full 6.9 kW, or still export 3kW while charging at 70A which is welcome flexibility albeit rather late in the season!

However since my round trip efficiency is <80% it is not worthwhile to charge the battery from Cosy at 12p merely in order to export more at 15p. So the aim is to leave as much scope to export PV consistent with starting the 1600h - 1900 peak period with a full battery to power the HP. Even Victron Dynamic ESS seems not to be very good it, so am still wrestling with automating the decisions using the standard Scheduled Charging function. At the last iteration I have 3 charging periods in the afternoon with targets of 40% SoC by 1400, 70% by 1500, 100% by 1600. Not sure it will export once the thresholds are met, if that does not work I will have to code what I want to do in NodeRed.