Development of Rechargeable Variable Laboratory Bench with Direct Current Power Supply System

Abstract

Unreliable grid electricity constrains laboratory teaching and research activities in many Nigerian institutions because conventional direct current power supplies depend on continuous mains availability. This study designed and developed a rechargeable variable laboratory bench with an integrated DC power supply and wireless monitoring system. The design provides an adjustable 0–24 V DC output, a maximum current range of 0–5 A, and a seven-cell lithium-ion battery pack rated at 25.9 V nominal and 29.4 V when fully charged. The system comprises an 18 V buck–boost output, 3.3 V and 5 V regulated outputs with a USB port, and a variable 2–24 V output. An Arduino Nano acquires voltage measurements through divider networks, while an ESP8266 module transmits the readings wirelessly for real-time monitoring. The design process involved circuit analysis, Proteus 8.0 simulation, hardware construction, and performance evaluation. Simulation results showed outputs of 12.00 V at the variable stage, 5.01 V at the 5 V rails, 3.30 V at the Wi-Fi rail, and 18.10 V at the dedicated 18 V channel. The charging section produced approximately 30.3 V DC from the stepped-down and rectified mains input. The monitoring algorithm simultaneously reported the three output channels. Under the reported test conditions, the system demonstrated stable voltage regulation, battery-backed operation, protective functionality, and reliable wireless monitoring. Further load, thermal, ripple, current-capacity, and long-duration battery tests are required to establish its full laboratory rating.