• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Build A Battery Low Alarm by Yourself

Status
Not open for further replies.

akabela

New Member
Hi Everyone, I want to share a BATTERY LOW ALARM BUILD project with you today.
FIFN9MBJ8AGQ9IQ.MEDIUM.jpg F5A5BEGJ8AGQA4K.MEDIUM.jpg

This project sounds alarm when the battery voltage falls below the user defined (low) voltage .It is used in 12 volt battery (It may be any type of Battery- Lead acid ,Lithium -ion, Lithium - Polymer etc.,) and it will produce audio and visual indication to us. It can be connected directly to Inverter Battery.

It uses IC LM358 as main component,which is dual operational-amplifier,used in comparator mode, with some active and passive components.The Battery low voltage can be set by user by adjusting Variable Resistor. For instance, Lead acid battery 10.7 Volt is considered as safe low voltage. Here I am setting the voltage of 10.6 volt for demonstration purpose.

Besides ,Viewers with some basic knowledge in electronics can do this Project.

The total cost of this project would around 3 USD.

The componets used in this project are given below:

1. LM358 IC

2. 1Kilo Ohm Resistor------------------------2Nos.

3. 4.7Kilo Ohm Resistor----------------------1Nos.

3. 10Kilo Ohm Variable Resistor-----------1Nos.( I am using Multi-turn Pot)

4. 1N5234B (6.2V ) ZENER DIODE-------1No.

5. 1N4007 DIODE-----------------------------1No.

6. BC 547 (or) 548 NPN Transistor--------1no.

7. LED (Small -3mm red) -------------------1No.

8. Buzzer 12 volt small ----------------------1No.

9. Two pin screw Header -------------------1No.

10. General Purpose PCB -----------------1No.(or) use my PCB which is 5cm x 3.7cm.(approx.)
The schematic circuit diagram is shown in step 1. You can use this circuit and you can make PCB circuit as your own or you can use my PCB layout readily available. In my Pcb use jumper wire at J-J. Make Print out and transfer it to copper sheet and do etching as regular process.Then pcb is ready. Make holes by drilling using 0.6 to 1.0mm bits as necessary.etc.,After choosing the PCB, solder all the components. check for any short circuit.



Step 1: Assembly
FO9NO6UJ80GO7UE.MEDIUM.jpg F21OADEJ80GO7XF.SMALL.jpg FYA98CRJ80GOBIY.SMALL.jpg FVQH6DCJ8AGQB0B.SMALL.jpg FT9WQKNJ8AGQBFF.SMALL.jpg



The schematic circuit diagram is shown in step 1. You can use this circuit and you can make PCB circuit as your own or you can use my PCB layout readily available. In my PCB use jumper wire at J-J. Make Print out and transfer it to copper sheet and do etching as regular process.Then PCB is ready. Make holes by drilling using 0.6 to 1.0mm bits as necessary.etc.. After choosing the PCB, solder all the components. check for any short circuit.





Step 2: Calibration / Setting Low Voltage
DC-DC Step Down converter.jpg


Using DC-DC step down converter or variable voltage source , set the voltage to 10.59 volts. Then connect this 10.59 volt to the Battery low alarm circuit. Adjust R3 multi turn pot in Alarm circuit , clockwise or anticlockwise until buzzer beeps and LED on.Hold on R3. Then increase the votage in DC-DC step down converter or variable voltage source to 10.65volts. Now you can see the Buzzer and LED stops.

Now the Battery Low voltage is set for 10.60 volts.




Step 3: Testing


Connect the Low Battery Circuit to a variable power supply and adjust the voltage slowly upto to 10.75 volts .Here I am connecting 3cell Li-Po battery to dc-dc step down converter . The output of li-po is around 11.1v , which is reduced by step down converter to around to 10.75 volts and it is fed into the Low Battery Circuit. since the set value is 10.6 volts and battery voltage is around 10.75 volts, Alarm doesn't work .Slowly reduce the voltage to 10.61 volts and when voltage reaches 10.59 volts the buzzer and LED becomes ON.

Application:
You can use this circuit in many fields . In automotive cars, almost all vehicles up to 24 volts, Inverters,UPS Burglary Alarms, and many more fields , etc.. Thanks for reading. If you have any questions/suggestions/improvements, please leave a comment below!:p
 

schmitt trigger

Well-Known Member
Congratulations on a well documented project.

I would suggest that you revise the component values to reduce idling current consumption.
This is very important in battery-powered applications.

Increase the resistor values 5X or 10X the actual values. Change the opamp to a low current type, like the LPV358. Finally replace the zener with a low Izt type like the 1N4627.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top