First Use of our Wallbox
First Use of our Wallbox
7 months ago, it was only a daring plan for his master’s thesis – now our 23-year-old working student Hendrik was able to carry out the first test charge with the wallbox he developed himself under the guidance of our CTO Henk Oldenkamp. And: The test was a complete success! “When the vehicle’s display jumped to ‘charging’ after plugging in the charging cable, I could have jumped in the air!” Hendrik says about the successful first test charge. The prototype works – now there are only a few steps left until the product will be ready for the market and can be mass-produced.
Wednesday, September 28, 2022, 7 a.m. in the parking garage Obere Königsstraße 31 (Galeria Kaufhof) in Kassel. Solarnative working student Hendrik and colleague Florian woke up extra early to pick up the rental car for a very special day: the Renault Zoe from car sharing provider scouter is our guinea pig for the first test charge with the in-house developed wallbox, part of our Smart Energy Home System. It is a very special project for Hendrik: In March 2022, he decided to develop a wallbox, the “EV Stick”, under the guidance of CTO Henk Oldenkamp for his master’s thesis of Electronics & Automation at Solarnative. After 5 months of concentrated development work and numerous tests, the circuit design and layout were set – now it was time to build the first functional version of the device in the laboratory. To this day it was uncertain whether the step from theory to practice would succeed immediately and whether the wallbox would successfully charge an electric vehicle. Consequently, working student Hendrik and all Solarnative colleagues in Lohfelden are super excited about this first test charge.
After arriving at the parking lot of our Lohfelden office with the rented Renault Zoe, preparations for the test start immediately. With a few screws, the EV Stick is attached to a wooden post that the team has placed at the edge of the parking lot for this purpose. Unfortunately, we’re expecting rain and the team has to improvise a little: Two large umbrellas are attached to the post and table leg with a lot of duct tape. They are intended to protect both the electronics of the laboratory wallbox and the laptop that is connected to measure various data from the rain.
Around 2:20 p.m. all preparations have been made. The entire team at our Lohfelden office has gathered around the test setup. The moment of truth has arrived: will the vehicle charge?
Filmed by colleague Florian, Hendrik takes the connection cable from the wallbox holder and plugs it into the charging socket of the Renault Zoe. The vehicle’s indicator flashes orange for a few seconds … and then turns blue: the vehicle is charging! “Wow! Wow, wow, wow!” calls colleague Manjesh from the cockpit of the vehicle and claps his hands. The test charge is a success! A proud moment for working student Hendrik: The proof of the success of his work has been provided – just in time for the submission of his master’s thesis next weekend.
The most important question has now been answered. But in addition to some measurement data that the team wants to collect on this day, there is another question to ask: will the vehicle charge at full speed with 22 kW when the battery is sufficiently discharged? So: hit the road and drain the battery a bit. Hendrik and Florian race down the autobahn for about an hour listening to rock classics on Radio Bob to discharge the battery to below 70%. Because if the charge level is too high, the charging speed automatically restrains to protect the battery.
After returning, the solar natives reconnect the vehicle to the wallbox. And another reason to celebrate! The measurement shows: the current flows with the target strength of 32 A, which corresponds to an output of 22 kW, from the wallbox into the Renault Zoe.
At the end of this special Wednesday, Solarnative is in high spirits. There are still a few steps to be taken before our EV Stick is ready for the market. But these are largely “hygiene factors”, such as installing an earth leakage circuit breaker and a communication chip, and finalizing the housing. The test showed, the functionality of our Plug & Play Wallbox is there.