12V Lead Acid Battery Voltage Monitor

Rajkumar Sharma      http://www.rajkumarsharma.com  
Project tested


This project is a 12V Lead Acid Battery Voltage Monitor


12V Lead Acid Battery Monitor is a simple project which tells you the voltage of your Lead acid battery visually with the help of 10 LED’s.  This project is based on the popular LM3914 IC from Texas Instruments.

The LM3914 senses the voltage level at the input pin and drives the 10 light emitting diodes based on the voltage detected on input connector. Circuit works on same battery, doesn’t not require separate supply input. Jumper is used to select the DOT mode or bar graph mode.


  • Supply input 15 VDC Max
  • Maximum and Minimum range selectable with onboard preset
  • Output 10 LED’s
  • 2 Types of display Bar and Dot selectable by a jumper
  • Very low current consumption, typical 100 mA
  • Header connector for connecting power / voltage in
  • Four mounting holes of 3.2 mm each
  • PCB dimensions 37 mm x 75 mm









5 Response on “12V Lead Acid Battery Voltage Monitor

    1. You connect the battery to CN1 and the LEDs indicate the battery voltage. In other words it’s self powered from the measuring voltage, no need for additional power.

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