someone can help me modify this circuit ??

[lazyhut]

because this circuit will never finish the charge..
someone can help me modify this circuit ??

**broken link removed**

here is the designer website https://shdesigns.org/lionchg.html

 

[MikeMl]

Does it really never finish the charge, i.e. revert to the lower voltage, or does it just never turn on the LED?

 

[Chippie]

There's nothing wrong with the circuit..it functions as designed by Scott...I've built several for charging lipo batteries and its a characteristic that the battery never appears full because the charging regime reverts to constant voltage with an end point of 4.22v/cell....so a small current will flow...but not enough for the led to remain lit...

You could add some sort of detection circuitry around the current sensing resistor to turn off charging but is it worth it...I think not..just disconnect when the led goes out

 

[ericgibbs]

The original circuit published in the LM317, 1994 datasheet works OK.

Just add an LED indicator.

 

[lazyhut]

thanks for reply
above the circuit will never finish the charge even less current it draws..

now my problem is how to modify it auto turn off battery charger when has been fully charged.

but i have no point to modify it..

 

[ericgibbs]

thanks for reply
above the circuit will never finish the charge even less current it draws..

now my problem is how to modify it auto turn off battery charger when has been fully charged.

but i have no point to modify it..

I would suggest you follow 'Chippies' advice, when the led goes out, disconnect the battery.