I know that many times we wanted to have a battery level indicator when we saw that some device or toy decreased its normal operation, That is why we will make a circuit that allows us to visualize the LI-ON LIPO1S battery level whose maximum voltage is 4.2

These circuits have many wireless power tools, to see what level of charge our battery is, we will make a very easy, economical but above all very functional circuit.

This project has few components and applying only the OHM law we can make our battery level indicator

In the circuit we can see that the first led will tell me if it is in 2.1v, the second at 2.8v the third at 3.5v and the last at 4.2v. The logic is simple because if the level is at 2.1v we add the breakdown voltage of the semiconductor diode of 0.7v to give me 2.8v what will be for the next led. Now if we add again 0.7v of D2 it gives me 3.5v and finally if we add the D3 0.7v it will give me 4.2v, then we will see that if we put a battery that is already a little spent, it will indicate 2.8v in 50% of the state of the battery, then we will see that it is fully functional.

The electronic components we use are:

·        2 red led diodes 5mm

·        1 yellow led diode 5mm

·        1 green led diode 5mm

·        3 semiconductor diode 1n4007

·        1 resistor 1/4w 150 ohm

·        1 resistor 1/4w 120ohm

·        1 resistor 1/4w 70 ohm

·        1 2-pin connector

The characteristics of the circuit are:

 - Efficient in measurement

- LIPO 1S LI-ION 4.2V battery measurement

- 3% measurement tolerance

This project is thanks to JLCPCB for the N°1 professional pcbs worldwide in the manufacture of electronic cards and electronic prototypes.

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