Help needed with schematic for 5V battery charger

Hello!



I am looking for a schematic to design and build my own PCB or PCM (protected circuit board/module).



It needs the following:

- 5V 2A input

- Charge 3 "14500" (14mm diameter x 50mm height) cells of 800mAh each in parallel.

- 5V 2A output



Might be awesome if the input could be directly redirected to the output when something is connected on both. This so the batteries wouldn't be used for nothing.

When nothing is connected to the output (or I might insert a switch in between) the batterypack will be charged.



Batteryspace.com told me I needed the following devices (and I quote):

"1. A charging board that will allow 5V input to charge a 3.7V Li-Ion battery



2. A PCB that offer over charge, over discharge protection.



3. An output step-up board that step up a 3.7V Li-Ion battery to 5V for output."



I think I need something like this, cause it looks this one does all:

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I might buy one of these for testing first.

Eventually I want to put the schematic on a board with specific measures; that's why I couldn't buy one which is prefabricated (and eBay usually offers bad quality products).

Software like KiCad and Fritzing should help me with this.



Thanks in advance!

Help needed with schematic for 5V battery charger