Charging a car via AC-IN or AC-OUT (230V socket instead of a charging station)

DIY
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1

Hi, just a general question; some background information first.

  • I always charge my car (currently a hybrid – 19.7 kWh) at 230 V. I’ve been doing that for 9 years now; I even managed perfectly well with my Tesla Model 3 (54 kWh or so).
  • I’ve had my Victron setup for 3 months now, and for the past 2 months I’ve also had a dynamic contract with DESS set to trade. (3-phase, 46 kWh, MP2 48/6k5/100)
  • The car’s socket is connected to the AC-out side.
  • During the recent holiday period (with hardly anyone at home), everything worked fine.
  • Since we’ve been back home (I’d already noticed it before then), things haven’t been going well with DESS/trading.
  • This is because the car is plugged in from around 17:00 and draws 2 kW for approximately 10 hours. However, DESS drains the battery around 21:00–22:00, and the car then continues charging at the ‘high’ tariff.
  • I activated the beta EV integration yesterday. It’s nice, but as far as I can tell, there’s not much I can do with it yet.
  • The car doesn’t handle the power being switched off and on very well – in other words, it unfortunately doesn’t automatically resume charging. (Volkswagen).

My questions are:

  • How have you solved this?
  • Idea 1:
    • Move the socket to AC-IN
    • Use a grid meter to distinguish between essential and normal loads. – I already have one at home.
    • Disadvantage: the car can’t use battery power for charging, and the car will still charge at the high tariff.
  • Idea 2:
    • Move the socket to AC-IN and upgrade to a Victron EV Charger NS.
    • Add a grid meter
    • Advantage: Victron can then also control the charging (which isn’t possible at 230 V).
  • Idea …? Do you have any other ideas, or am I thinking about this the wrong way?

I’d really appreciate any advice. At the moment, I find it frustrating to see that the trading still ends up with me having to pay for the electricity…

Thanks!

2

why does it do that? That’s where the problem starts, isn’t it?

3

That’s what I do—I get home and plug the car in.

Then it charges at 2 kW, which I can’t control either because it’s connected to a 230 V socket.

And Volkswagens aren’t really customisable…

4

I’m still new to the forum myself, and to Victron and home charging. But I’m looking into it as well.

I read that OCPP will soon be available in the beta version, but that’s for EV chargers.

In your case, could a Shelly smart plug and Node-RED be a solution?

5

A new EV charger from Victron is coming soon, with a few more features.

With ESS, charging from the batteries on the AC-in side is also possible (with or without an additional energy meter).

6

I have to admit, I don’t understand the problem here.

I have a BMW/Keba wallbox and use EVCC to tell it to charge only when there’s surplus PV power.

EVCC communicates brilliantly with the Victron Venus ecosystem.

What more could you improve?

7

Thanks, the problem is that I’m using DESS in trading mode. The car is also never plugged in when there’s a solar surplus (>17:00).

So DESS runs the battery flat and then charges the car with expensive electricity, because the car is “dumb” (connected to a 230 V socket) and charges all the way to 100%.