myenergi Zappi project page

As some customers have correctly noticed, I now also sell a car charger, also known as a wall box, in my shop. I chose the myenergi solution because it offers a smart and ecological solution for using photovoltaic energy.

I also use this wall box myself for my vehicle, which I received in June 2021 after a waiting period of 8 months.

Part 1: Planning

First you have to think about where to put the wall box. Since it is also suitable for outdoor use as IP65, there are several options. I chose to install in the garage because that's where the vehicle will be most of the time.

Then the problem: wiring. We need to run the power and data cable from the meter closet to the garage. So it's clear: It has to be drilled, and a big hole at that. And once the lines have been fed through, this must also be sealed watertight again. We decided on a house connection entry, so you can insert the cables and close them directly thanks to the shrink tube ends. We close the actual bore with fountain foam (waterproof).

The meter cabinet must be checked to see whether there is still enough space for the new components. It's good that I have a large closet, everything still fits in here.

And very important: Before installation, EnBW (or the responsible power grid operator) must have given approval (if 22KW power, with 11KW only notification is required)

However, there is a problem if you want to receive government funding for connecting the wall box: the charging station must then be limited to 11KW.

Part 2: Installation

First of all: You should never do the installation yourself, but must be carried out by an electrician or specialist company.

For my installation, I chose the 22KW variant because as an entrepreneur you do not receive any state funding for the installation - only private individuals receive this.

However, my electrician then immediately informed me that the existing 22 mm² lines on the meter field are NOT permitted for 10KW, these must be replaced with 16 mm² lines. That would be a legal requirement that 22KW instead of 11KW may be tapped. The supply line to the Zappi can be 5 wires with 10 mm² wires. You also need your own fuse (3x fuse is the cheapest way) and a meter (that was my wish, because I want to measure the charging current independently).

A cable must also be laid for the sensor terminals (3x CTs were supplied). The CT lines are quite long at 6 m, but the 15 m to the charging station are too short for me. According to the manual, twisted pair cables should be used for this so that the data is not falsified. So I simply took an 8-wire network cable Cat5e, which I had left over (orange in the picture). By the way, cable glands were NOT included, but my electrician had some.

For the house and garage breakthrough, we chose a location that ends in the basement right next to the meter cupboard and leads easily out of the garage. The house connection is laid through the hole in the house and garage and sealed there. In order to get the appropriate depth, we removed some stones and then dug about 20 cm deeper. Next sticking point: we drill from the inside out and have to find the exact position. Luckily this can be calculated by using another hole as a guide. So we ended up exactly where we wanted.

In the house it is then necessary to find the best way. We opted for "long on the ceiling" (pictures are from before sealing with fountain foam):

And then on counter+fuse

We clamped the CT clamps to the respective phases above the house connection meter (unfortunately a little hard to see because the rail is in the way).

Oh yes: The clamps must sit at right angles on the cable, preferably without play. I cut 16x3cm pieces from a 3 mm pipe and put them in the clamps. I had to find that out first, because the system brought up strange error messages like “Installation limit exceeded” and incorrect display of the current values.

If the menu now appears in the Zappi display, then the most important steps have already been completed. There are also various information displays in the Zappi menu, which should confirm that 3V is present on all 230 phases.

The electrician should then carry out and log the safety measurements in the Zappi and thus complete the installation.

3. HUB

The myenergi HUB connects the Zappi to the internet. Zappi and the hub communicate wirelessly and the hub transmits the data to the internet via its Ethernet connection. With the myenergi app you can display the data.

But before that you have to connect the hub to the Zappi: press the Pair button on the hub. Now you have 120s seconds on the Zappi to select "search for devices" in the menu and connect the hub. This worked for me straight away. The hub with its registration ID then also appears under Information/Page 2.

To register the hub for the app, you must first enter the SerialNr (back of the hub) and then the registration ID. Then enter a password and the energy values ​​appear in the app!

4. Loading

Actually totally unspectacular and boring...just loads.

So there are 3 charging modes: Fast, Eco and Eco+.

• FAST: Fast loads without limitation. As fast and as much as the vehicle can charge or in which Zappi is configured as the maximum value.
• ECO: With Eco, it always charges the minimum charge, i.e. approx. 1,4 kW or the value that the vehicle has defined as the lowest value. If excess energy comes from the PV system, for example, then the Zappi gradually increases the charge until the excess energy is balanced. If no excess energy is available, the minimum value is charged anyway.
• ECO+: This mode is like ECO mode, except that there is no minimum charge value. So only excess energy is charged. However, this does not work with all cars. After a while, mine complains that there is no charging and stops charging if there is no excess energy. **UPDATE** : Since the Zappi firmware update 3.142, it has worked flawlessly with my Ford Mustang Mach-E!

So I always switch between ECO and FAST: If I have an appointment first thing in the morning and the car is not yet charged in the evening, then I also switch to FAST. But if I'm in the home office and the car stays in the garage, then I switch to ECO. ECO+ actually only works when the car is stationary for a long time.