EV Charger on AC-Out and ESS

[adochitei (Adrian)]

Hello,

I have a Victron ESS system and I’m trying to find the best configuration for EV charging.

My system

• MultiPlus-II 48/5000
• Cerbo GX (Venus OS v3.75)
• ET112 on the grid connection
• 15 kWh Dyness battery
• Victron EV Charging Station
• ESS in “Optimized (with BatteryLife)”
• EV Charger connected to Inverter AC Out

What works

During the day the EV Charger works very well in Auto mode.

Example:

• PV = 4 kW
• House = 0.4 kW
• EV = 3 kW

The EV charges almost entirely from solar surplus.

My goal

During the night I would like:

• House loads supplied from the battery.
• EV charging supplied only from the grid.
• I do not want to cycle the home battery just to charge the EV battery.

Charging one battery from another battery does not seem efficient and creates unnecessary battery cycles.

Current behaviour

When PV production is not sufficient, ESS starts discharging the battery to supply the EV charger.

Even with:

• Allow battery/grid power for auto mode = Enabled

the ESS still prefers the battery.

My questions

1. Is there any supported way to tell ESS:

“Do not discharge the battery for EV charging, but continue using the battery for normal house loads.”

2. Would moving the EV Charging Station from AC-Out to AC-In solve this while still preserving proper Auto mode solar surplus charging?
3. Is there any planned feature such as “Prefer grid for EV charging”?

I think many ESS users would benefit from such an option.

Thank you.

[lxonline (LX)]

I think you will find there is a way to do this with node red already.
There are other users on the forum who have made solutions for this for themselves, but no everyone is a developer.

A recent one under beta development is called opportunity loads. It is in the testing oahse so feel free to join in. (You are right is is a good idea for a feature.)

BETA: Turn surplus solar into useful work with GX Opportunity Loads

We are excited to start BETA-testing a new GX feature: Opportunity Loads. Opportunity Loads increases self-consumption by automatically using surplus solar energy for flexible AC loads such as: EV charging Water heating and thermal storage Pool pumps Charging e-bikes Other controllable AC loads The GX device acts as a system-level energy coordinator and dynamically distributes available surplus across supported devices. [Screenshot of the Opportunity Loads configuration scre…

[Vince31 (Vince Williams)]

If you NEVER want to charge your EV from your home battery, and just want to charge your EV from the grid using overnight cheap rate, then there is an easy and permanent way to do this. However, you’ll need to change your house wiring so that your EV charger is the first thing connected to the grid input from the meter cabinet (via its own separate Henley Block connection) . Your Multiplus is then connected downstream from this, again on it own separate Henley Block connection, your Grid meter will need to be positioned between these two Henley Block positions so it doesn’t see the EV charger demand. This configuration means your Multipluswill never see the EV charger as a load and will not dump the battery contents into the EV. Any excess PV (after your house battery is full) will still go to charge your EV. This is how my system is configured.

[dognose]

You could just connect the EVCS between the Grid Meter and the Multiplus’ AC-IN.

Then, it can charge solar, it will be recorded and shown as loads, and with the Setting “Self-consumption from battery: Critical Loads only” nightly EV-charging will be punished to grid automatically.

If you have other loads on ACIN which you want to be supplied from battery this won’t work. Then a simple Node-Red Flow toggling that setting during EV-Charging may be good enough.