Breakout board incorporating the 3.6-3.7 volt Li-ion single-charged battery charger (4.2 V full-charge), based on the integrated MCP73831T SMD encapsulated in a SOT-23 case manufactured by Microchip. The card accepts in input (on SOL contacts) typically 5 volts, which can come either from a common power supply, either from a miniature photovoltaic panel, but also from the USB connector of a computer. From the SOL contacts, the supply voltage reaches the input (VIN) of the charge regulator MCP73831T, which accepts voltages of the order of 3.75 ÷ 6 volts at the input and supplies to the output the current needed to charge elements lithium-ion or lithium-ion (Li-Po) polymers delivering up to 550 milliamps. The battery (to be connected to the +/- BAT contacts) can have a theoretically unlimited capacity, because at most it loads in a very long time, however considering that with a current of 550 mA a 550 mAh element is charged in one hour, one of 1,100 mAh for charging will take 2 hours, one from 5.5 Ah will need 10 hours and so on. In the breakout board the integrated works in the standard configuration that sees the light diode LD1 powered (by the resistance R1 - connected to the contact PROG- which limits the current) from the output STAT, which is placed at a low logic level during charging , while it remains at a high level at the end of the charge; the same leads to high impedance (open) when the MCP73831T is shutdown or at the VBAT output no battery is currently connected. This last output (pin 1) is the line to which the battery is connected. Dimensions (mm): 22x22.