Chip allows you to create the right chargers, moreover, it is cheaper than the untwisted MAX1555.
A typical wiring diagram is taken from the datasheet :
An important advantage of the circuit is the absence of low-impedance power resistors that limit the charge current. Here, the current is set by a resistor connected to the 5th pin of the chip. Its resistance should be in the range of 2-10 kΩ.
Charging assembly looks like this:
The microcircuit heats up quite well in the process of work, but this does not seem to interfere with it. Performs its function.
Here is another PCB version with smd LED and micro USB connector:
( Download this board in * .lay format)
Perhaps this is one of the simplest charge for lithium-ion batteries 18650, which can be done with your own hands. Suitable for li-pol batteries.
If the current in 500 mA is not enough, I recommend to pay attention to the circuit with TP4056 .