Build Your 9V Ni-Cad Battery Charger Circuit

Description

This automated NiCd charger for 9V NiCd batteries leverages the characteristics of the 555 timer and is remarkably straightforward to assemble. Why is an automatic 9 volts NiCd battery charger favored? Because a battery can remain in the charging process for as long as desired; it will consistently be entirely charged and prepared for use when required. It avoids overcharging and prevents discharging. Utilizing the values outlined in the circuit diagram, the NiCd battery charger circuit is appropriate for both 6V and 9V batteries.

9 volt varieties with 6 and 7 cells are charged at a current of 20mA; P1 needs to be adjusted to ensure that the NiCd charger disconnects following a duration of 14 hours. The lower limit setting is configured at 1V below this value with P2. A 5V battery type incorporating 4 or 5 cells receives a charge at 55mA. Once more, with P1, adjust the NiCd charger circuit to trigger disconnection after 14 hours. The inferior level setting must be established at 0.8V below this value.

Circuit diagram:

Parts:

More about components

The 555 timer (IC) is a versatile integrated circuit functioning as a precision timer and oscillator. This particular IC, a commonly used component, allows for the creation of various time delay circuits. It operates by utilizing a positive feedback loop, creating an astable multivibrator circuit that repeatedly switches between high and low states. The timing of these transitions is controlled by external resistors and capacitors, enabling the generation of different pulse widths and frequencies. It’s crucial for building time-based circuits and is readily available in various package types for easy integration into a circuit design. The IC is known for its stability and ease of use in numerous applications, including timers, oscillators, and waveform generators. It’s a fundamental building block in electronic projects, and its widespread availability contributes to its popularity and utility.