TP4056 USB-C Li-Ion Charger

A single-cell lithium charger module — your first SMD solder build, end-to-end.

Difficulty: Surface-mount. Estimated build time: about 90 minutes. Estimated parts cost: about US$8.00. 9-part bill of materials with live supplier pricing. A self-contained linear charger for one 18650 or LiPo cell, built around the TP4056 — a tiny 8-pin SOP that handles every awkward part of lithium charging in hardware: the constant-current ramp from 0 V, the constant-voltage hold at 4.20…