Development of portable power supply units applying Li-ion batteries

For electrical or civil engineering work at night or work inside manholes where there is no permanent power supply unit, generators with diesel engines or similar devices have conventionally been used. Since a generator produces noise, careful consideration for the surrounding environment must be taken, especially when it is used at night. To address this and other issues, portable power supply units that use Li-ion batteries were developed. This paper describes the characteristics of the portable power supply units, Li-ion battery monitoring and management technology (BMCPU), and various measures to improve serviceability, followed by results of system performance experimental tests.