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battery monitoring circuit

Hi.
i want to check my battery status by using the circuit which i have attached.I am using 12v 4.5Ah battery.when i fully charge the battery it gives more than 12v.What i exactly want is that when battery voltage is 12.5v all the LED's will be ON.when battery volts becomes 12v two LED's will be ON,when battery volts becomes 11.5 one LED will be ON and if battery volts becomes less than 11.5v No LED will be ON.Reference voltage i am using is 5v.
My question is that how i find the values of resistances so that when voltage of battery increases/decreases then LED's will light up accordingly.
thanks
 

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change the 5v zener to 6.2 v much better knees for those guys . must understand there is a +/- % variation from that voltage. looks you got comparitos and the output cannot push more then 8ma so the led will be dim. YOU NEED TO PROVIDE SOME HYSTERISI for each like 10 ua positive F/B for each. the resistance is your choice for 12 v assume 1 ma so 6.2v/1ma 6.2k and 5.8k I recomend using lm3914 to do this one part 2 resistors. simple.
 
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