1.5 V battery level indicator

Thread Starter

EmaCO2

Joined Apr 24, 2018
11
Hello,

I'm in need of a simple circuit for indicating the charge of a single 1.5 battery via a single or a couple of LEDs.

Ideally, full operative charge is shown by a green LED, but when level goes below a certain threshold, let's say 0.9V, green LED goes off and red LED goes on.

Another interesting option could be a red LED blinking at a slow frequency when the battery is full, progressively increasing the blinking frequency as the charge decreases.

Do you guys think it could be feasible?

Thank you!
 

Thread Starter

EmaCO2

Joined Apr 24, 2018
11
I forgot to mention that the battery will be powering a 0.8-3.3V to 3.3V step up voltage converter.
Thus there would be a reference voltage of 3.3v, even while the battery goes down.
I guess could be useful having a reference power...

Thanks again!
 

crutschow

Joined Mar 14, 2008
34,469
An LT6550 opamp/reference would also work.

The cheapest approach may be an TLV431 reference with an LM339 comparator operating from the 3.3V.
 
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