Solar charger for cell phones

During the planned project activities, the Citizens’ Association Ekosol also implemented a workshop ” Solar Chargers for Cell Phones”. This is a multi-year idea that we have been developing at the association and the basic idea was to create a mobile phone charger that can be installed in places where there is no accessible electrical grid, so that citizens can charge their mobile phones outside. In 2016, we made our first version of the charger for which we received funding, but after a while, we became convinced that our design had certain flaws that needed to be repaired if we wanted to make our charger reliable.

From the county project, we provided ourselves with the funds we needed to get started ,and a new version of our charger was created, that had an advanced design so it could be placed on a larger range of holders. We also carried out a workshop for secondary and elementary school students as part of the project activity, where we showed how the charger design itself looks and how it can be applied. Our participants also enriched their knowledge in the field of photovoltaic systems of their components and parameters.

More about the charger:

The charger is designed to collect solar energy during the day and store excess energy in the battery. There are USB terminals on the charger that are connected to the voltage regulator. Energy is directed by the charge regulator, which represents the “brain” of the system and determines how the energy from the photovoltaic panel will be distributed. In case there is enough solar energy, the controller directs the energy directly to the USB sockets that charge the cell phones, and in case it is dark or very cloudy then the energy is drawn from the battery. When there is no cell phone connected, the controller stores the excess energy, the controller directs the excess to the battery, which is then charged. This system enables optimized use of energy and provides constant power to the device. The photo below shows parts of the charger. The battery is a large black object and it takes up most of the space in the box, the charge controller is located above the battery (photo above). As it can be noticed, it contains lights that serve as indicators for energy income, power draw and the level of charge of the battery. The white cable goes to the photovoltaic panel, while the small plates hanging on the other white cable are voltage regulators 12 / 5V.

As seen in the previous picture, all the charger components except the panel are protected in a weatherproof plastic box to protect these components. The charger is designed so that it can be mounted on a wall or bracket, such as street lighting. The following figure shows the appearance of the assembled charger:

The black cable is used to connect the cell phone and can be done in various ways depending on the need.