EV Charger on AC-Out and ESS

Q&A and troubleshooting
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1

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.”

  1. Would moving the EV Charging Station from AC-Out to AC-In solve this while still preserving proper Auto mode solar surplus charging?
  2. 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.

2

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.)