Uno：
Shindengen began selling AC chargers in 2013. The service life of AC chargers is said to be approximately 8 to 10 years, and the year 2023, when the camouflage AC chargers were released, was exactly the time when products installed in the early years of AC charger sales were due to be replaced. There was an internal decision to develop an updated AC charger that would meet the needs of the current EV charging infrastructure market in preparation for this replacement timing.

During the product planning stage, we gathered feedback from businesses that install EV chargers, and we heard comments such as “We want to be able to choose and introduce EV charging services independently” and “Installing the EV chargers involves some high hurdles”, so we thought that there was a need for a product with a high degree of freedom that would meet these market needs.

Takahashi：
The concept of the camouflage AC charger is that it can be installed in various places in any location, such as on the ground or on a wall. Of these, the ground-mounted units in particular were at risk of vehicles driving over them, so it was necessary to design a compact, lightweight casing that could be installed anywhere while also achieving the strength to withstand the weight of a car.

In addition, since this is the first time we have installed Bluetooth®, we needed to use a resin material for the casing that would not block radio waves. Since resin is weaker than metal, one of the issues was how to achieve a high level of strength. While simply increasing the thickness would ensure strength, in order to achieve a lightweight, compact casing, it was necessary to “select materials” and “examine shapes” that would ensure strength while making the casing thinner.

This process was very time consuming. In particular, the optimal shape was studied through repeated strength simulations, taking into account the pressure exerted by the tire and the size of the tire. We went through a lot of trial and error, such as reviewing the shape of the areas where the stress was concentrated, and then dispersing the stress to other areas, which weakened the parts that were not previously a problem.

We were able to achieve the target performance without any damage in the final test in which an actual car was driven over the product.

Yamashita：
The only certification standard for AC chargers in Japan is the certification conducted by the Japan Automobile Research Institute (JARI). Only products that have passed strict certification standards to ensure the safety and compatibility of EV chargers can obtain this certification, so it is one of the deciding factors that allows businesses that install EV chargers to choose and use EV chargers with peace of mind. Furthermore, since chargers that have been certified are eligible for the “charging infrastructure subsidy”, they can contribute to reducing the financial burden on businesses that install EV chargers.

The camouflage AC charger also obtained certification from JARI, but it did not progress as planned. During the certification process, we found that some parts did not meet the standards for waterproofing, so we needed a new structure. As this was the first time we had used this structure, we had little knowledge of it, but through repeated communication with JARI, we were able to complete a product that met the standards.