Module as bought from ebay.
US$2.10 each (make offer for bulk purchase)
These modules come configured for LiFePO4 cells and 2A charging, for standard Lithium cobalt oxide cells or different charge rates there are minor mods to be made.
schematic diagram, modified from the chinese version to match the actual module.
Also here are the part numbers/values for the PCB itself.
R1 1.2kohm ?
R2 0 ohm
R3 R050 => 0.05ohm 50mOhm 2A charge
C1 0.1uF Vreg
C2 10uF Vin
C3 10uF Bat
C4 10uF Vs
Diagram showing the location of components to modify.
Light blue: short this with wire or '0' ohm resistor to switch for 4.2V standard lithium ion charging voltage.
Purple: Current sense/limit resistor, see table below for values.
(Note if you connect the lithium ion battery in reverse by accident, this resistor is the part that burns out.)
note: small 'm' denotes mili prefix, which is 1/1000th
All resistors are SMT 1210 size (3.2x1.6mm)