Comimark 1Pcs MCP73871 USB DC Solar Lipoly Lithium Lon Polymer Charger 3.7/4.2V Battery Module

Does what it was designed for which is why I bought it. I'm just developing my project, but once I've settled on the design, I'll probably remove the status LED and make other minor changes to save energy. I will eventually optimize the design for low energy consumption and improved efficiency.

Sort of works, but there are options that work way better. First of all – no documentation whatsoever. I had to resort to reading the datasheet on the chip and following traces on the PCB to figure out what some of the solderable holes on the board are. Secondly – while the chip can in theory support 1A charging, the SMD resistor installed on the board caps it at 500mA. Yes, you could in theory replace it, but if you have SMD soldering capability, you're probably not buying this board anyway. Finally – get yourself an IP5306 based charging board and your own capacitor. It's smaller, cheaper, and simpler.

Yeah, some documentation would have been nice but the data sheet is available online for the chip.

Package arrived today; no documentation of any sort. No contact information; only two bar codes with no meaningful imformation. Header pins; no way to indentify header pin, connection uses. No imformation about thermistor selection.