18 February 2010

Low-battery indicator circuit

I designed this little circuit to show a battery’s status.

It lights an led to show the battery is OK, and will change to show another colour when the battery’s low.

The transistors can be any npn-type, and the leds can be any colour (in the diagram, green=ok, red=low)

The operating voltage range is ~3v-12v, and by adjusting the resistor values it will work beyond that.

The voltage the low led comes on at, is set by the potentiometer.
by at 18:50

3 comments:

  1. offtherails201027 Apr 2012, 10:28:00

    Hi Daftmike !!!

    Many many thanks for sharing this simple circuit for everyone!!!

    I have since made 4 stripboard circuits AND 4 PCB's of this Low Battery Indicator !!!!

    As i have only started learning electronics i had found your instructions from your post on ModRetro extremely easy to follow because you used pictures and made it idiot-proof, lol !!!

    Truly AWESOME !!!

    Thank you so much!!!

    A.K.Sethi

    ReplyDelete
  2. dgm_mixtoon1 Aug 2016, 02:50:00

    great!
    for my modded power bank!
    thaks!!

    ReplyDelete
  3. Unknown7 Dec 2021, 20:43:00

    Is there a way to modify this circuit such that at particular low level of the battery, say 11volts, a buzzer alarm would sound, and also when the battery gets further lower, say 10.5volts, a connected relay would disconnect the battery from a given load?. Thanks

    ReplyDelete

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