Set of 2 – BMS Module 2S 20A 7.4V with Balancing – Protection Board

Main Advantages

• Active Balancing — equalizes cell voltages during charging for extended lifespan.
• Complete Protection — Over-Charge, Over-Discharge, Over-Current, and Short-Circuit (resettable).
• Wide Compatibility — supports 18650, 26650, and 3.7/4.2V Li-Po cells.
• Compact Design — perfect for small tools, DIY projects, power packs, and mobile systems.
• Easy Wiring — clearly marked connection points: 0V, 4.2V, 8.4V, and output terminals +/−.

Proper Connection

Connect the batteries as follows:

• Cell 1: 0V (−) → 4.2V (+)
• Cell 2: 4.2V (−) → 8.4V (+)
• Final Output is available at the + and − terminals on the board.

Note: On first connection, the battery must be charged to activate the output. Do not mix batteries with very different capacity or internal resistance.

Technical Specifications

Charging and Usage Information

• Recommended charging voltage: 8.4–9.0V.
• BMS automatically limits charging current to 10A.
• For high loads, ensure proper cooling or reduce current.
• Suitable for applications up to 50W or resistive loads below 168W.

Compatibility & Applications

Suitable for:

• 2S Li-Ion packs (DIY, panels, power packs)
• Small power tools and robotic projects
• Portable devices and modified systems using 18650/26650/LiPo cells

Safety Notes and Best Practices

• Do not mix a good cell with a degraded one.
• Respect polarities 0V / 4.2V / 8.4V according to the diagram.
• On first connection, charge the pack to activate the output.

Package Contents

Set of 2 × BMS 2S 20A — Balancing Version (48×20×3.4mm), ideal for 7.4V Li-Ion packs with advanced protection and cell balancing.