Hello everyone,
I need help to make circuit for as battery disconnect from charger than glow LED and also want to command MCU for reset battery status as battery full to stop glowing charging indicators. And can i make without using relay with help of MOSFET, op amp, transistor

 

Hi Gurm,
Welcome to AAC.
Is this a Homework or College project?
E

 

I've used a comparator for that duty. The LM339 is four comparators in one IC. You can place a low-ohms (eg. 0.1Ω) shunt resistor between the battery's negative pole and the charger ground, and then one comparator can watch the voltage on that shunt resistor. Even a tiny current will trigger the comparator and indicate that a battery is connected.

The other comparators can be used to indicate various voltages on the battery's positive pole. You just need to set the reference voltage for them to compare the battery against.

 

What is the battery type and voltage?

make circuit for as battery disconnect from charger than glow LED

What exactly does that mean?
Do you want the battery disconnected when it is fully charged?

 

Do you want the battery disconnected when it is fully charged?

I think I misunderstood the original task, and that you have guessed correctly. Maybe one LED that goes off and another turns on (or a color-changing LED changes color) when charging has completed? My automotive battery charger does just that. It also includes what I was alluding to: the same LED is red when nothing is attached. There is no power on the alligator clips at that point and that avoids any shorting of the clips while handling the charger. Power is only delivered once a small voltage is detected.

I'd still use comparators to deliver this functionality unless the MCU can do it. Well, actually I'd prefer to use a dedicated battery management IC.

 

Are you talking about modifying an existing charger to disconnect the battery when an LED “charging complete” indicator goes on? That should be quite doable.