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can i make battery life indicator that tells whether the battery is low?

the battery indicator is like in the cellphone; where you can tell that ur phone needs to charge.

frollard7 years ago
A battery meter isn't anything special - it just measures the voltage of the battery and compares it to what the batter should put out at full charge.  Say a battery is charged at 1.5 volts and dead at 1.1 volts, then you just convert the measured difference (.4 volts) to 0-100% charge.

You can go a step further by sensing how much current is being drawn, and using the known capacity of the battery you can estimate the battery runtime remaining.

Long story short:  There are several circuits for this:

http://www.bowdenshobbycircuits.info/page11.htm#meter.gif

http://www.google.ca/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=PRB&q=low+battery+indicator&btnG=Search&meta=&aq=f&oq=
Re-design7 years ago
Sure.  What are the details of the battery?