LiFePO4 Charger

This project a charger for a LiFePO4 battery, it’s main use is to charge Cricket2 modudles, these have a 3.5mm socket which connects to the plug on the charger.

Two power sources are intended as the input to the charger, a mains driven generic “floating” PSU, or a solar panel.

The charger demonstrates the building something useful from nothing, or building from junk principle.

LiFePO4 Housing Assembly

The housing is a plastic box that used to house a drill bit. The switch/voltmeter/Charger board/and other components were all items I had from previous projects.

Also the external 12V PSU is from a previous purchase.

External PSU

Schematic

Charger Module - 5A lithium battery step-down charging board LED power converter step-down module XL4015

Links

This is AliExpress

Specifications

Input: IN + input positive, IN- input negative
Output way: OUT + output positive, OUT- output negative
Input voltage: 4-38V
Output voltage: 1.25-36V continuously adjustable
Output current: adjustable, maximum 5A
Output Power: 75W maximum
Working temperature: -40 to + 85 degrees
Operating frequency: 180KHz
Conversion efficiency: up to 96%
Short circuit protection: Yes (limit current 8A)
Overtemperature protection: (automatically shut off the output after overtemperature)
Input reverse polarity protection: None, (if necessary, please enter the string into the high current diode)
Installation: four 3mm screws
Module dimensions: length 51mm width 26mm height 15mm