A remote-controlled PWM power management board for small (10 W - 20W) solar panels, connected to either lead-acid batteries, or trickle-charged Lithium ones (12 V target in both cases). Designed to be as much through-hole as possible, and to only use LCSC components. Has MOSFET-controlled outputs, most of which are PWM-capable. The circuit is designed for about 3A max current on any single line, including the solar & battery ones. PCB designed for this enclosure: https://www.aliexpress.com/item/5PCS-Plastic-Electronic-Project-Box-Shell-Case-Enclosure-Instrument-Case-100x60x25mm-10x6x2-5CM/32850410579.html This version uses PWM to keep the battery charged. The exact algorithm and voltages are set in firmware. There are ports for a 433 MHz ASK/OOK receiver module, HC-06 Bluetooth module, and a HC-12 module (sharing ports with the Bluetooth module), as well as for an I2C OLED display and an AM2320 temperature & humidity sensor.