Compact 1A MPPT Charge Controller Module for singlecell lithium batteries. Designed to charge 3.7V nominal Li ion and LiPo cells, including 18650, to the standard 4.2V charge voltage. The module performs maximum power point tracking from a solar panel input and regulates charging with a constantcurrent constantvoltage profile and a 1A current limit. Bare board format without pins requires soldering or custom wiring for installation. Key benefits Maximizes solar charging efficiency: MPPT function extracts more usable power from small solar panels compared to a direct connection, improving charge times in variable light. Reliable cell charging: Regulates charging to 4.2V and limits current to 1A, providing a proper CC CV charge profile for singlecell lithium batteries. Easy integration: Compact PCB module fits into DIY projects, retrofits, and small enclosures. No preinstalled pins lets you choose your own connector style and wire routing. Versatile compatibility: Works with singlecell 3.7V nominal lithium chemistries including 18650, LiPo and other Li ion cells. Important attributes Function: MPPT solar charge controller with CC CV charging behavior and 1A current limit for singlecell lithium batteries. Compatibility: Singlecell lithium batteries 3.7V nominal, charge target 4.2V, including common 18650 cells and small LiPo packs of similar voltage. Form factor: Compact PCB module supplied without pins or connectors, for soldered or custommounted installations. Construction: Standard PCB with surface mount and through hole components suitable for lowpower solar charging applications. Performance: Designed to improve charging efficiency from small solar panels and provide steady regulated charging up to 1A. Installation notes Module is without pins. Solder wires or connectors to the board according to the marked input and battery terminals. Verify correct battery polarity before connecting. Use appropriate wiring and fusing for your setup. Intended for singlecell charging applications. Do not connect multicell packs in series without a proper balance and management system. Typical applications Small offgrid sensor or data logger powered by a small solar panel and a single 18650 battery for extended outdoor operation. DIY portable power bank or handheld light where a singlecell Li ion battery is recharged from a picnic or backpack solar panel. Solar garden light replacement controller or small offgrid charging station for hobby electronics projects. What you get A dedicated 1A MPPT solar charging module sized for singlecell lithium batteries. Module does not include pins or external connectors. This module is suitable for electronics hobbyists, makers, and technicians who need a compact, MPPTenabled charger for singlecell lithium battery projects.