Whilst supercapacitors are now commonplace and reasonably affordable, the use of Lithium Ion capacitors is increasingly offering significant advantages in energy density and voltage supply range. This tiny board uses an AEM10941 IC from E-Peas to create a highly efficient solar harvesting system for Lithium Ion capacitor charging.
Combine this board with a small solar cell and a lithium ion capacitor and you can create an MPPT capable charge system that is efficient enough to charge the capacitor with indoor lighting. When the lithium ion capacitor has over 2.58 V the capacitor is charged up to 3.78 V and a regulated output supply is enabled with 2.2 V with up to 80mA available. The IC tracks the maximum power point every 5 seconds and so this should make a small but capable supply for small sensor projects, such as efficient LoRa nodes.
The board is supplied with all the SMD components soldered and comes with 2.54 mm header pins unsoldered so it can be mounted onto a project or used on a breadboard. On the product page there are some example power measurements and data around Lithium Ion capacitor efficiency and suggested reading if you wanted to convert the board to output 3.3V.