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Battery-free Innovative Solar Charger

Battery-free Innovative Solar Charger

Tsuji plastics Co., Ltd.

Compact Charger to Provide Inexpensive Electricity and 
Light That Rural Residents Need


ccess to electricity in rural areas in developing countries is still not easy. To make electricity available to these areas, easy and affordable services are needed. To solve this problem, we have developed a solar charger that uses no batteries at all. It is easy to use and does not require battery replacement. Therefore, there is almost no maintenance cost required.

Fig. 1 Main concept of the Solar Charger

Major Features and Advantages

    Technical features

    1. Compact and easy to handle solar charger
    2. Expected product life is over 10 years
    3. Almost no maintenance cost
    4. Simultaneous charging from 8 USB ports
    5. An environmentally friendly charger that does not generate battery waste

    Technology Data

    Possible applications

    The solar charger has very low maintenance costs and can provide charging services with low running costs. The solar charger can be used to easily charge mobile phones and radios, which are in high demand in rural areas.

    When you use our rechargeable LED lanterns, children can easily study at night, which will help to fill the education gap. For those who rely on kerosene lamps for nighttime lighting, LED lanterns provide not only sufficient lights, but also help to prevent fires that can be caused by flames and the risk of physical harms.

    Fig .2 The usage of Solar Charger

    Competitive advantage

    1. Ultra-long life

    The solar charger we developed applies a unique energy storage system that hardly deteriorates even after repeating charging. The charging performance does not also change through its use for an extended period and we have achieved an unconventional long product life.

    1. Excellent life cycle cost

    Since it is intended to be used in developing countries, the initial installation cost is low. This is no need to replace the batteries, and the charger costs almost nothing to maintain and provides an excellent life cycle cost. It can provide affordable electricity to people in unelectrified areas in the developing countries.

    1. Eco-Friendly Specifications

    Conventional solar power generation systems require periodic replacement of storage batteries, such as lead-acid and lithium-ion batteries. These batteries are not suitable for the environment because they contain heavy metals. The products we have developed do not require batteries and are environmentally friendly.


    Technical features

    1. Expected life expectancy is over 10 years.
    2. Simultaneous charging from 8 USB ports.
    3. Input: 12V, 100W (recommendation).
    4. Outputs : 5V, 5A / 8USB ports.

    Technical Maturity / Past record of introduction

    This solar charger is a brand-new product launched in August 2019.

    Thus, it has only been tested and introduced in Uganda. However, other products which have similar power systems have been sold for more than 20 years in Japan.

    We have received a purchase order from Senegal. We are going to ship our brand-new products to Senegal in September 2020.

    Information on patent related to this technology

    (Applying) PCT/JP2020/ 5927

    Company Data

    Name Tsuji plastics Co., Ltd.
    Address 160 Gokashooku-cho, Higashiomi-shi, Shiga 529-1423
    Capital 10 million JPY (as of September 2019)
    Contact person Mr. Yoshikatsu TSUJI
    TEL: +81-748-48-2206
    Corporate website:
    Number of employees 35 (as of as of September 2019)
    Date of company foundation
    31st October, 1988
    The type of business
    Manufacturing industry


    International operation

    Number of employees for international operation 
    City, Country Name of Company (if applicable)
    Dakar, Senegal
    Sentech Energy

    Modality of business transaction

    Direct Investment

    We invite local people to our company for technical training and technology transfer. These people will be responsible for the operation of the local subsidiaries as representatives. We are planning to procure some parts locally.


    We want to become partners with local companies or local entrepreneurs to transfer our technology. These companies will be in charge of maintenance, promotion.

    Export of product

    Only when requested by a public body.


    Schematic illustration of the technology


    Contact Person(s)

    Mr. Yoshikatsu TSUJIE-mail:

    *Please mention that you saw UNIDO's website when making the first contact with the company.

    Registered Category

    • Energy Technologies : Renewable energy
    • Environmental Technologies : Circular Economy (3R)