Adding a battery charger into my circuit

I have this schematic already but my team wants to use a rechargeable battery. I can’t find the symbol or footprints for it anywhere and I am unsure how to connect it inside the circuit. Does the power go through the charger as in I connect everything to it or to the battery?

This is the schematic.

Just create a rectangular symbol that represents the board. No need to show the internal circuit. The footprint will be a rectangle the size of the board with holes and pins at the correct positions. As far as you’re concerned the charger board is a black, er yellow, box.

Ok but how should I connect it in relation to the other components?

That I don’t know, you’d have to consult the datasheet. It’s a circuit design question not a KiCad question.

However I’m guessing this is an integrated battery management board. You connect a LiPo battery to the battery port, send power in via the USB-C port and it will provide power on the USB-A port, drawing current from USB-C or the battery and charging the battery when necessary. As I said, you need the datasheet to check it out. You could ask in circuit design forums where people have used this board.

I do not know what you are powering. But what you describe sounds like it could use an “ideal diode” or “ideal OR’ing diode” circuit. Basically this draws power from either the battery or (the USB?); whichever voltage is higher.

The function is similar to just using diodes. If you can tolerate losing 300 - 400 mV, then go ahead and just use schottky diodes, maybe ones rated for 20V - 30V. (In general, schottky diodes with lower reverse voltage rating also have lower forward voltage drop.)

But if that is not good enough, then go with the ideal diode route:

  1. I think LT (now Analog Devices) makes a chip for that. Maybe other manufacturers do as well.
  2. I have designed a couple of circuit options using MOSFETs and op amps.

26076-Use_op_amps_to_make_automatic_ORing_power_selector.pdf (1.5 MB)

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Are you also asking the warnings and error you have shown ? If yes you need a ‘PWR_FLG’ on both the 5v line and the GND line and connect the 2 GND pins on the Arduino together, thats your error. For the warning you will have to check yourself as the 3 pin device SEN-11574 is custom ? and Kicad can’t see it in a libary or try updating from libary in the devices property window. Are you sure that JFET is driven correctly ? If I’m completely off target please disregard what I have said in its entirety :zipper_mouth_face:

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