In this project, we will show you a battery monitor circuit that can utilize to monitor the voltage of 12V lead-acid batteries. For example, vehicle batteries. Here is a simple Battery Monitor circuit for a brisk check of a 12volt Lead-Acid Battery. The circuit fabricates with the help of the LM3914 and a few other components with 10 LEDs which will indicate the voltage level.
Battery charge should be continually observed to monitor the life of the battery. Overcharge as well as undercharge will decrease the battery life. The terminal voltage of the Lead-Acid battery should be within a certain range such as 12 to 13Volt. In the event that the battery voltage lessens beneath 10 volts for a long period, the battery won’t accept any charging current. Thus, if the terminal voltage surpasses over 14 volts, the battery will be devastated.
Hardware Components
The following components are required to make Battery Monitor Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC | LM3914N | 1 |
| 2. | Variable Resistor | 5K, 200E, 10K | 1, 1, 1 |
| 3. | Resistors | 4.7K,1.2K | 1,1 |
| 4. | Electrolytic Capacitor | 10µF | 1 |
| 5. | LEDs | – | 10 |
| 6. | Diode | 1N4001 | 1 |
| 7. | Battery | 12V | 1 |
LM3914 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM3914
Battery Monitor Circuit
Working Explanation
The main component of the circuit is LM3914 which associates with 10 LEDs via some resistors and capacitors. These LEDs will help to show the voltage level. A couple of hardware needs for adjusting the circuit for a 12volt battery. One is the lab power supply and the second is a digital voltmeter. To start with, you need to interface the digital voltmeter to pin 4 and pin 6 of the IC.
And adjust the variable resistor VR2 for a reading of 1.2 volts and make VR1 and VR3 in their center settings. The circuit is ready to use if the VR1 voltage range ends at 4.5 volts.
Applications and Uses
- This basic battery monitor circuit utilizes to monitor the battery and other voltage sources of current.
- Battery monitor circuits are also used to test the battery charging status.
