UPDATE: https://www.circuitsdiy.com/usb-li-ion-charger-revision
This is a simple li-ion charger without a dedicated li-ion charger IC. This circuit can be used to efficiently and intelligently charge any single cell Li-ion battery pack like mobile battery, digicam battery, etc.
There are 3 LED on the circuit. One LED will be always on whenever a battery is connected. Another LED will blink continuously to indicate charging and the third LED will glow when battery charge complete.
We can charge these Li-ion battery packs with direct regulated voltage but these batteries require special charging technique for long lasting.
These are than when battery charge is less than 20%, charging voltage should be low, not a constant and when battery is full, i.e, charging current almost zero, charging should stop.
In this circuit, the both conditions are checked with the 1R resistor which is in series with the battery.
You can connect USB port’s 5V supply here, and also can connect any other 5V supply.
Li-ion Battrery 9 v Battrery experiment can
LM358 aren't available in my country ?
where do you live
please pcb diagram
HELP how do this relay works
What values needs to be modified to charge a 12 volts battery?
I presume you're referring 3 Li-Ion batteries in series. It's a tricky job to charge Lithium batteries in series.
Awesome approach..I believe I seen this elsewhere in b/w schematic but detailed version only here. Just one thing, what's the o/p charging current? Can it be increased to 1 or 1.5A? What will be new component values? Best.
I use lm324 ic,but when voltage battery reach 3.67 volt,the charging LED stop blinking,how to modification the circuit until voltage battery reach 4.2 volt,please send me notif or update circuit picture,thank all
Its working well but if lm358 is not available which ic is equivalent to it?
Can this circuit works fine using it to charge 4.2v batteries connected in parallel??
Ofcourse. But both batteries should be identical.