Ideas for battery power on/undervoltage indicator?

[Martinn]

Hi all,

I like battery operated circuits. The problem with those however is that you should supervise the voltage somehow. Mostly I just have an LED plus resistor (e.g. 1k for a 9V battery), but that does not really help because the LED is still lit if the battery is almost completely dead.
Useful range for alkaline cells is 1.6 down to 0.9 V, so 5.4 to 9.6 V.
It would be nice to have an indicator that (as an example) is green above 6 V and red below.
Current drain should not be much more than the 1 mA needed for the LED.
Bonus:
Bipolar supervision (+-9 V)
Lower cell counts (2 or 3 cell)

Components should be from the JLC basic library https://jlcpcb.com/parts/basic_parts as they are almost free of charge (I have almost all my designs built by JLC), except for a common anode/cathode dual color THT LED.

Quick idea below, does not really feel super elegant.
Abusing a TL431 perhaps?

Ideas?

- Martin