Engineering High-Efficiency 18650 Charging Arrays: Transitioning from TP4056 to FM5324 10W Synchronous Boost Architectures

Description and use

Switching from linear TP4056 to FM5324 raises charging efficiency to 93 %, provides 5 V/2 A output, and simplifies wiring by removing separate boost modules.

Problem

Linear TP4056 chargers limit current to 1A, generate heat, lack native boost, and are inefficient for high‑capacity Li‑Ion cells in parallel arrays.

Outcome

Switching from TP4056 to FM5324 increased charging efficiency to 93%, enabled 5V/2A output, reduced heat, and simplified wiring by eliminating separate boost modules.

Workflow

• Select FM5324 PMIC for 18650 charging array
• Configure Type‑C input for 5V/2A fast charging
• Use internal MOSFETs for synchronous rectification
• Enable dual‑purpose substrate to output stabilized 5V via USB Type‑A or PCB header
• Monitor SoC with 4‑stage LED driver or analog voltage scaling in C++
• Deploy matched‑resistance Zaritech Standard Series 18650 cells for uniform discharge
• Integrate firmware library from Zaritech Labs GitHub for telemetry

Evidence

The classic TP4056 operates as a linear charger. This means any voltage drop between the 5V input and the battery’s cell voltage (ranging from 3.2V to 4.2V) is dissipated entirely as heat.

Source

The FM5324 is a fully integrated synchronous switch‑mode solution managing both buck‑charging and boost de‑charging simultaneously at 5V / 2A (10 Watt).

Source

By replacing standard diodes with internal low‑resistance MOSFETs, the conversion efficiency climbs up to 93%.

Source