BMS 2S 20A with Balancing for Li-Ion 7.4V Packs (Set of 2)
Overview
Set of 2 BMS 2S 20A boards (7.4V nominal / 8.4V full) with balancing function, designed for protection and management of Li-Ion battery packs (including 18650 and 26650). Provides full protections: overcharge, over-discharge, overcurrent, short-circuit, and automatic reset. Compact size, ideal for DIY projects and portable devices.
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.
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
Feature
Value
Type
2S BMS Module with Balancing
Nominal Voltage
7.4V (2 × 3.7V)
Charging Voltage
8.4V – 9.0V
Overcharge Protection
> 4.3V
Over-discharge Protection
< 2.3–2.5V
Overcurrent Protection
25A
Recommended Continuous Current
20A (may require heatsink)
Short-Circuit
Yes, resettable (~200ms)
Charging Current Limit
10A
Dimensions
48 × 20 × 3.4 mm
Balancing Operation
“430” resistor heats up during charging — normal
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.
Photo Gallery
Reviews
There are no reviews yet.
Be the first to review “Set of 2 – BMS Module 2S 20A 7.4V with Balancing – Protection Board” Cancel reply
Reviews
There are no reviews yet.