EV charger behaviour/settings questions

Hi All,

I've got the GE EV charger installed a couple of weeks ago to work alongside my current kit (GE Gen 3 Inverter, GE Gen 2 9.5KWh battery and Renault 5) and so far I'm having issues getting it to work together how I'd like. Whilst I understand the inverter and think it works great, so far I'm not impressed with the software integration for the charger into the GE ecosystem. Am I being dumb and not understanding how the system works or is what I'm trying to do only possible with HACS or via a future update?

I'm on the Octopus Agile tariff and so what I'd like the system to do is;

1. Solar output charges the house battery first, then the EV, then exports to the grid.
2. EV shouldn't charge from the house battery, the EV charge rate should be dropped if the PV output drops.
3. The EV only charges from the grid when I instruct it to on an adhoc basis (i.e. Agile prices are low/negative).

The idea is that I can leave the EV plugged in to trickle charge (without affecting the house battery) and then top it up from the grid when I need to boost the EV's charge or if the electricity price is right.

The settings I've left unchanged are;

• Charging mode = Solar.
• Config = Inverter Control.
• Prevent Battery Discharging to EV = Enabled.

The settings I've tried changing, the effect and my questrions/obervations are.

The schedule

• The EV only charges when a schedule is active and there isn't a way to create a 'default behaviour' which a schedule deviates from (e.g. like 'Eco' mode on the inverter where a forced charge/export from the battery can be timed).
• You can't create a schedule that changes the charging mode?
• The "charge current limit" is the only means to restrict the charging rate on the EV and you can't set this dynamically based on PV output within a schdule.
• So you can't use a combination of schedules to mimick how the inverter operates (i.e. an always on solar schedule which is disabled when a grid/hybrid schedule is ion the same time slot).

Solar Priority.

• Prioritising this to the battery means it doesn't charge the EV at all, even if the house battery is full (i.e. it exports when it should be charging the EV). I presume this isn't intended and it should divert excess to the EV after the battery?
• Prioritising this to the EV means it does charge but at a fixed rate determined by the amount of PV when it starts. The EV charger then takes energy from the Battery to maintain this charging rate. This charge rate is set by automatically adjusting the current limit. Again, I assume this isn't intended and it should reduce the charge rate (to a min if 1.4kW) if the "Prevent Battery Discharging to EV" setting is enabled?

Other questions

• I understand that solar charging start until there is a 1.4kW surplus over house load, what's the reaosn for this and can this be lowered? Having a 5kWp PV system in "sunny Yorkshire" means there's plenty of time where the house load is covered but struggle to hit the 1.4kW excess.
• Is there a roadmap or similar with what GE are planning for the EV charger and future software updates? It definately feels like the poor relation comparted to the inverter/battery.

Thanks for your help!

[unknown] I understand that solar charging start until there is a 1.4kW surplus over house load, what's the reaosn for this

This is a feature of the signalling behaviour between (any) AC chargepoint and car. The charger tells the car how much power is available, and the min. is 6A.

DD
Yes. Minimum charge rate is 1.4kW for all EV chargers (not just GE one).

The GivEnergy EV software isn’t very flexible. For example you can only have one active Schedule set. Try turning on Plug and Go if you haven’t already but I think you will have to manually intervene a lot which will be a pain.
Have a look at this from Speak to the Geek. It’s for automating with Intelligent Octopus Go but it might give you some tips on how to use Home Assistant for your requirement.
https://youtu.be/Xy_DoXlJ8HA?si=8P1nRbHmveJ0-9DB

Maltbyite I'm on the Octopus Agile tariff

Have you considered an EV tariff instead ? While agile does have occassional price dips, looking at
https://energy-stats.uk/octopus-agile-southern-england/
the average price doesn't seem to go below 14p. Whereas Go gives you reliable overnight at 8.5p, for example. Then it's simpler just to unconditionally export excess solar (15p) rather than trying to mess around using it to charge car.

octoprice may be able to help you decide which tariff works best. (But it must be frustrating that you can't just make it do what you want. I ended up with a Zappi - I needed untethered, and GE don't offer that option.)

I agree with DD. It’s a set and forget option. With IOG the rate is 7p. As long as Octopus support your EV model. Then set a GivEnergy app schedule to charge from grid from 23:30 to 05:30. Your house battery will charge at the same 7p rate and you can export all day long at 15p, Yorkshire sun permitting, because you will wake up to a full battery.

Until reasonably recently the above worked fine for me:
Plug in the car (Peugeot e208) during the day
If the sun shines >1.4kw it diverts to the car. A % can be allocated to the battery as well to ensure it doesn't remain uncharged
At night the overnight tariff kicks in and the full 7.4kW charges the car
And if needed I can hit the "Charge Now" button and it'll charge at 7.4Kw

However it stopped doing this a couple of months back.
I raised a case, they turned on plug & go. This just starts full 7.4kw charging the moment your car is plugged in - not at all the right solution!

It's not for money, it's just to reduce needless energy consumption.

If you get any resolution I'd be interested!

Until reasonably recently the above worked fine for me:
Plug in the car (Peugeot e208) during the day
If the sun shines >1.4kw it diverts to the car. A % can be allocated to the battery as well to ensure it doesn't remain uncharged
At night the overnight tariff kicks in and the full 7.4kW charges the car
And if needed I can hit the "Charge Now" button and it'll charge at 7.4Kw

However it stopped doing this a couple of months back.
I raised a case, they turned on plug & go. This just starts full 7.4kw charging the moment your car is plugged in - not at all the right solution!

It's not for money, it's just to reduce needless energy consumption.

If you get any resolution I'd be interested!

From the research I've done, it does seem like some cars/chargers can lower the 6A/1.4kW starting level but it's exceptionally rare and limits the peak charging rate too - thought I'd try my luck though!

I have seen a few of Speak to the Geek's videos but that was ages ago so probably should rewatch them.

Switching tariffs is my back up plan if I can't get the EV to behave as I like but haven't done so yet as (i) I've only had the car 3 weeks so don't really have enough data to crunch the numbers yet and (ii) I like the 21p/28p export rate of the Flux Export tariff, which you can't have on the EV tariffs.

So with the restriction of 'one active schedule' can you practically do solar charging in addition to the Octopus Go times (even if it's not sensible to do if it's then costing you 15p/KWh instead of 8.5p/KWh)?

[unknown] like the 21p/28p export rate of the Flux Export tariff, which you can't have on the EV tariffs.

So charging car from solar effectively costs 21p/kWh, whereas charging overnight from grid would be around 16p or so?

Will very much depend on your mileage whether flux works best for you.

Maltbyite From the research I've done, it does seem like some cars/chargers can lower the 6A/1.4kW starting level

Yes, the chargepoint signals the max rate available (min 6A), but the car actually chooses how much to take. Some allow you to set a level lower than 6A.