This article introduces the concept of deep discharging in batteries. Deep discharging has the potential to destroy the batteries. With a simple circuit you can protect your battery.
This is an under voltage Protection Circuit for 12V Battery that shuts off the load when the voltage drops below a set value.
When the battery voltage rises to a set value, the module automatically restarts the load.
Under Voltage Protection Circuit Diagram
Here is a very simple Battery Deep Discharge protection circuit with only a few components. You can design your own PCB to make this circuit watch video for making process of this low voltage battery protection circuit
Parts List For 12V Battery Low Voltage Cutoff Circuit
- Transistor 2N2222 or use any NPN Transistor 1pc
- Diode 1N4007 1pc, Zener Diode 9.1V 500mw 1pc
- Multiturn Trimmer 10K 1pc
- Resistor 4.7k 1pc, 1k 2pc, all 1/4watt
- LED 5mm any colour 1pc
- Relay 12V 10amp or as per your Load Current
PCB Layout For Battery Over Discharge Protection Circuit
Save image Below and take a print on A4 size paper no need to any adjustment in image. How to make a PCB for this Circuit ? Please watch video Below. Also you can Download Gerber file for this under voltage battery protection circuit from link below
How Battery Under Voltage Protection Circuit Works
For deep discharge protection, we need to identify the cut-off voltage of the battery. After that, we need to design a circuit in which, when the battery reaches the cut-off voltage level, a Relay disconnects the load from the battery.
For cut-off voltage identification, we will choose a Zener diode 9.1Volt. A Zener diode in reverse bias condition will act as an open circuit when its cathode is applied with voltage below breakdown voltage .we used a 10k variable resister with diode’s anode point to set the cut voltage as per our need. When the cathode voltage is above breakdown voltage, it starts conduction.
We will use a Zener diode with Zener voltage equal to the cut-off voltage of the battery and 10k variable resistor to do some adjustment in cut off voltage of battery. When the battery voltage drops below the cut-off voltage, the Zener diode will cut off the conduction and obstruct the flow of the base current of NPN transistor, thus disconnecting the battery from the load.