Kann ich mein E-Auto mit 6 Ampere Solarstrom laden?
E-Driving

Can I charge my electric car with 6 amps of solar power?

Why your wallbox does not need phase switching

Anyone who uses solar power from their own roof to charge their electric car saves money and increases the proportion of self-consumption of their PV system. In practice, however, the question arises: How sensible is it to charge the electric car even when there is little PV surplus available – for example, in the morning or evening hours? This is where the term "phase switching" often comes into play. But what is behind this – and is this function really necessary?

What does phase shutdown mean?

An electric car typically charges via three phases with up to 11 kW of power. To charge at all, the vehicle requires at least 6 amps of current per phase – equivalent to approximately 4.2 kW for three-phase charging (3 x 230 V x 6 A). If this minimum value is exceeded, the vehicle will refuse charging.
Some wallboxes therefore offer the option of automatically switching to single-phase charging when PV surplus is low. In this mode, a single circuit is sufficient – ​​and around 1.4 kW (230 V x 6 A) is enough to charge the car.

Sounds clever – but it isn’t

Technically, phase switching works, but the effort is considerable. The hardware must be significantly more complex, making it more expensive, and reliable switching during operation is anything but trivial. Moreover, the benefits are negligible:

  • Extremely small time window: The situations in which only single-phase charging is possible, but not three-phase charging, are limited to about 30 minutes to one hour per day – usually in the morning or evening.
  • Minimal power output: In this short time, charging is only possible with about 1.4 kW – i.e. around 10% of the possible charging power.
  • Economically inefficient: The additional technical effort is disproportionate to the solar power generated. The additional costs amount to several hundred euros/francs for a range of less than 10 km per day.

Case study:
Spring day with 15 kWp PV system

Graphic of a PV system
Solar power production: Daily course of the generated photovoltaic power
Household consumption: base load from household appliances and infrastructure
Possible phase switching: time window for single-phase charging
(approx. 30 minutes each in the morning and evening at approx. 1.4 kW – corresponds to about 10% of the possible charging power)

A typical spring day with clear sun shows the effect clearly:

  • 6:30 a.m.: The PV system delivers 1.5 kW – too little for three-phase charging.
  • 7:00 a.m.: The sun rises, the yield jumps to 4.5 kW and continues to rise – the car can charge three-phase.
  • 9:00 a.m.: The full 11 kW of solar power can be used for charging.
  • 7:00 p.m.: The power drops again to below 4.2 kW – theoretically possible single-phase charging.
  • 7:30 p.m.: Sun gone – no more PV yield.

In total, a maximum of 1.4 kWh of energy would have flowed into the battery in these two 30-minute windows – not even a range of 10 km .

The better solution: battery storage instead of phase switching

Anyone who seriously wants to use as much PV power as possible should invest in a home storage system. This allows solar power to be buffered and used specifically when the car needs to be charged – even at full charging capacity.
The JUICE CHARGER me 3 deliberately dispenses with automatic phase shutdown. Instead of offering a complex, custom solution for a barely relevant situation, the wallbox focuses on what matters: efficient, safe, and standard-compliant charging at full power.

Conclusion: Phase switching is a technical mistake

Yes, there are wallboxes with phase-switching. No, they're hardly useful. The effort is disproportionate to the benefit. Those who want sustainable charging rely on an intelligent, integrated system with a PV system, energy storage, and future-proof charging infrastructure – for example, the JUICE CHARGER me 3 .

Fact check:

  • Electric cars require at least 6 A per phase for charging.
  • 3-phase charging requires at least approx. 4.2 kW.
  • Single-phase charging with approx. 1.4 kW is possible, but slow.
  • Time windows with insufficient PV power for 3-phase charging are rare and short.
  • Phase switching is technically possible, but complex.
  • PV power can be used more effectively with storage.

Detailed information about the JUICE CHARGER me 3 can be found at: https://juice.world/collections/juice-charger-me-3

Our video provides even more exciting insightsJUICE CHARGER me 3 – the wallbox for all occasions