Battery Status Monitor Circuits

 

Battery is a common part in electronic gadgets now days. The battery is used to make the design portable. The charger coming with the battery doesn’t always contain the LED indications for the charge status. Here are few circuits which can be put at the output of any charging adaptor to show the battery status.

The circuit is build across the general purpose commonly available dual comparator IC LM358. The circuit makes use of both the comparators to show the status. The zener diode D1 is used to generate the reference for both the comparators.

When the power is ON or the battery is fully charged then the red LED D3 is turned on and if the battery is still in charging mode then the green LED D2 is turned on.

The circuit consumes negligible operating current and that also from the adaptor itself. So it doesn’t require any other power source for its operation.

The next circuit comprises of transistors and the zener diodes for their working. In the normal condition or at the state of battery charging the transistor Q1 is off so the LED D3 is on and when the battery is charged the transistor Q1 conducts and LED D2 is on.

LED D4 is used to show the power indication.

The next circuit consists of the shunt regulator TL431 and it only shows the charged indication. When the battery reaches the full charge voltage the regulator U1 conducts and the LED D1 is on.

All the circuits are presented here based on their accuracy.

Aniruddh

Ani-Lab