Speras - Universal Dual‑Slot USB Lithium‑Ion Battery Charger

The Universal Dual-Slot USB Lithium-Ion Battery Charger is a highly versatile, dependable charging solution engineered to meet the demands of professionals and enthusiasts who use a wide variety of rechargeable cylindrical Li-ion and Li-poly cells.

This compact, portable charger supports an extensive range of battery formats, from small 10440 cells to large 32650 sizes, including popular formats such as 21700, 20700, 18650, 17670, and 14500/16340, all with nominal chemistries of 3.6 V/3.7 V.

Powered via a standard USB Micro-USB input at 5 V ± 0.25 V/2 A, this charger can be connected to virtually any USB power source, including wall adapters, portable power banks, and USB-enabled solar panels.

Its smart CC/CV (constant current / constant voltage) charging profile intelligently manages power delivery, offering up to 1000 mA for a single battery or 2 × 500 mA when both slots are in use, ensuring efficient and tailored charging performance.

Each of the two slots is equipped with independent bi-color LED indicators: red to indicate active charging and green to indicate a fully charged battery.

The charger’s internal circuitry automatically stops charging once the battery reaches a cut-off voltage of 4.20 V ± 1 %, protecting cells from overcharging and preserving their long-term health.

Safety is a core feature of this unit, with integrated multi-level protection including safeguards against overcharge, over-current, short circuit, over-temperature, and reverse polarity.

The housing is constructed from flame-retardant ABS material with side ventilation fins to facilitate heat dispersion during extended charging cycles.

This charger is well suited for a wide variety of applications: everyday recharging of flashlight, vape, and power tool cells; field charging via power banks for photographers, campers, and outdoor professionals;

safe top-ups for batteries in medical or security gear; and support for DIY electronics, robotics, or battery-pack prototyping labs.

Designed for technicians, field operators, and demanding users, it delivers efficiency, safety, and flexibility in a compact, transportable format