As a result of the necessity to power portable gadgets that have increased in number in the previous decade, battery technology has progressed with time. Rechargeable batteries function similarly to primary cells, with the exception that their chemical processes are reversible. The goal of this project was to create a system that would show the capacity level of a Nickel Metal Hydride battery when it was charged and discharged. Because of its popularity among customers, the Nickel Metal Hydride battery was chosen for this project. The device, however, may be used to evaluate other types of batteries because the theory behind rechargeable battery technology is similar. A battery charger circuit and a discharge circuit were designed and built as part of the system implementation. After it, there was software design. A LM3914 driver IC is used in this project to drive 10 LEDs by delivering adequate current through it. The reference adjustable pin and the reference out pin control the brightness of the leds. The project’s purpose was met, and the findings were given in the form of numbers, charts, and indicators. The method is supposed to aid in battery planning in order to avoid device halts during operation. The findings of the study indicate that battery waste may be decreased. It was also mentioned that there is a better technique to handle batteries in order to conserve capacity.



A circuit that checks the battery life is known as a battery level indicator. With the help of LEDs, we can quickly determine the battery level. It makes use of an LM3914 driver IC to drive 10 LEDs by providing enough current through it. The reference adjustable pin and the reference out pin control the brightness of the leds. In order to have variable input voltage at pin 5 of the driver IC, a variable resistor is also included in the circuit. Because the driver IC has two modes of operation, bar graph mode and dot mode, we may display the battery life in either bar or dot form. We can use coloredlods to indicate the state of the batteries, similar to how we use colouredlods to indicate the state of the batteries.

As a result, the depiction of battery life will be made easier to understand by employing various colored leds. We can enhance the voltage range of the battery input by cascading the driver ICs. There are four blocks in the block diagram below. The power supply is one of them. Other than that, there’s the driver IC itself. A led block and an input block will be used. For the purposes of comparison, a reference input is provided. The leds will light up in response to the input and the reference input.

The voltage ranges from 12 to 18 volts. 1.25mV is used as the reference voltage. Any dc signal within the power supply’s range is assessed, and the level is displayed by the leds. The current flowing through the leds is regulated.

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