@Homemade 101, The output voltage for charging 3.7-4.2 volt cell is set around 4.7 volt between diode and led pin. The cell will be exposed for charging to 4.7 volt which is not healthy for a li-ion cell. Moreover the completion of the charging and the final voltage of the cell was not shown to asses the correctness of the proposed circuit. Now my two questions are for you to reply. Qn 1) Any explanation or correction required for setting 4.7 volt for charging. Qn 2) BC 547 can deliver 0.1 amp only for charging. Is this current enough? Will you please respond?
It's been a long time since I made and used this circuit to charge my led emergency lamp.I was afraid my battery( got from a broken power bank) would catch fire and explode if it was not auto cut off when fully charged.This circuit you show us helps me great, it automatically cuts off and I am very relaxed without any worry whenever I charge my battery. Thank you so much.
@madhusudangupta You are right!!! They have no knowledge about this components. It might be copied diagram from others whatever you said about charging voltage. Yes , it should around 3.7 to 4.2 for output voltage (Agreed). Over voltage can explode and he used bc547 whos output amp 100mah, thats not enough for charging faster.
Regarding the BC547: It is not supplying the charge current, that is handled by the relay. But I'm not sure how it can cut off. I will build it and try.
@101, The most lovely heart on my comment makes me to understand that you have not understood a single concept of my comment and so you have given me the Heart as if it is a Noble Prize. My Dear 1.01 I would love to get a considered reply including your suggestion if any otherwise consider yourself as an ignorant pseudo expert.
NO TRABAJA, NO FUNCIONA. Se calibra a que corte en 4,2, se carga la primera celda, se pone en verde y OK se quita la celda. Luego queda en verde y al intrudicir una nueva celda descargada (probe de todas las tensiones) no se vuelve a activar la carga el rojo de sin mover el trim (preset). O sea, cada celda hay que corregir y hacerlo cortar manualmente.