Hi, I want to make solar charge controller and i need suggestion to make it

[Farrel]

My idea is to build voltage detector with 5V Regulator and a Resistor Divider Connect to an OpAmp, the output from the OpAmp will connect to a Mosfet to limit the cutoff Voltage

This is my current design

i need your suggestion about the design and how to make the cutoff Voltage and how to prevent the battrey from undervoltage

[Codebird]

That is a rather unconventional circuit. Trying to feed an op-amp with a value potentially outside of the rails? I suppose it might be possible to make that work, with a careful choice of op-amp, but it is unconventional to say the least. Also, you have no backfeed diode, and your layout is hard to read.

[Farrel]

Thanks for your feedback i will redesign with more conventional OpAmp and place a backfeed Diode 
 
do you have any solution for the OpAmp?

[Farrel]

Revision circuit Design

[fourtytwo42]

I am afraid there are many things wrong with your circuit and you would be better posting it in the beginners section to get some help, just for starters the LM324 input common mode range does not include VCC and you will need a lot more than 5V vgs to properly turn on the mosfet. Its also drawn in an unhelpful way, try thinking most positive voltage at the top of the sheet and most negative at the bottom

[Farrel]

Hi, Thankyou for your suggestion, i will ask at beginner section