How to get a battery auto cut its current when its voltage decreases to safe level?

[Nicholas]

I m using a RECHARGEABLE battery to power a circuit during Mains power failure.
So, is there any way to get the battery self cut down its current when its voltage down to a safe level?
Thanks

 

[IanP]

low battery cutoff circuit

If I understand correctly, you would like to cut-off your battery when the battery riches certain voltage level (you called it safe level).
In this case you can use low current op-amp or comparator as comparator and a P-channel Mosfet as switch.
If voltage drops below this level the P-channel will be switched off..
Is this what whould you like to do?

 

[nicleo]

an almost-ideal low-battery cut-off circuit

There is a schematic on low-battery cut-off circuit in this article:

An Almost Ideal Low-Battery Cutoff Circuit Draws Only 1.2 μA
**broken link removed**


By the way:

Because your circuit is a battery powered unit you cant use normal comparators which will drain lot of power. You can use low power CMOS comparator to detect undervoltage.

Also, you may find many circuits/projects on battery monitor, management, charger, etc. in Circuit Celler Magazine , which you can download them FREE from this board at .

Here is another related project:
NE555 Low Voltage Battery Disconnect Circuit
**broken link removed**

Hope they help.

 

[platonas]

battery low voltage cut off prject

Hello,
From what you describe, I believe you need a Low Voltage Battery Disconnect circuit.
If you performe a search in Google with the above 4 words, you will find a lot of circuits.
Try also the following url **broken link removed**

You might find some other useful circuits and data there.
Regards
Platonas

 

[yigiter]

simple low battery cutoff circuit

you only need a "UNDERVOLTAGE SENSING CIRCUIT". so you could use an IC like MC34064. if you check the spec sheet, you could find the needed circuit.