DIY battery level indicator

Technology

By Collin Cunningham

Collin Cunningham

July 9th, 2008 4

Flickr member Kc7fys built this fine little voltage meter to indicate battery level using a bi-color LED and an LM358 op-amp chip –

I could measure the resistance values and just use regular resistors to make it smaller. It tells me when my radio power supply (battery pack) is 12V or above, 11-12V, or below 11V with three colors in the LED.

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4 thoughts on “DIY battery level indicator”

The Oracle says:

July 14th, 2008 at 3:27 pm

You’re not really powering an LED battery tester at 10-40mA (1-2 colours on), off of the battery under test long-term, are you?
Joseph Podejko says:

August 9th, 2011 at 5:59 am

Could this work for 5-6 volts?