SPECIFICATIONS

Smart Battery Guardian! 3S/4S/5S 100A High Current BMS Protection Board with Active Balance for Li-ion/LiFePO4, Ideal for DIY Power Bank, Solar, E-bike Projects.

Key Features & Benefits

Flexible Configuration, One Board for Multiple Uses: Supports 3S, 4S, or 5S battery packs (shipped as ordered). No modification needed. Ready for various voltage systems.

100A Robust Power, High Performance: Built with 15 ultra-low Rds(on) MOSFETs (3mΩ). Handles up to 80A continuous discharge (separate port) and 60A charge/discharge (common port).

️ Dual-Chemistry Design, Precision Protection: Pre-set for LiFePO4 (3.2V) and Li-ion/Polymer (3.7V). Full protection suite: Over-charge, Over-discharge, Over-current, Short-circuit, and Temperature.

️ Active Balancing, Extends Lifespan: Automatically balances cell voltages during charging, improving pack consistency and maximizing capacity & cycle life.

️ Industrial Reliability: Operates from -20℃ to +65℃. Compact PCB design for durable performance in various environments.

Product Description
Seeking the ultimate safety solution for your DIY lithium battery project? This smart BMS integrates multiple hardware protections with active balancing, making it the ideal core for building reliable power banks, solar storage systems, e-bikes/e-scooters, robots, or UPS backups. Compatible with two major battery types, it's the trusted choice for makers, hobbyists, and engineers.tection Board

【Critical Pre-Purchase Notes!】

【FIRST RULE: CHOOSE THE CORRECT BATTERY CHEMISTRY!】 Wrong choice can cause incorrect protection, leading to overcharge (fire risk) or failure!

If your cell nominal voltage is 3.2V (LiFePO4), you MUST choose the SKU with “LiFePO4-3.2V” in the name.

If your cell nominal voltage is 3.6V or 3.7V (Li-ion/Polymer), you MUST choose the SKU with “Li-ion-3.7V” in the name.

️【Wiring & Series Confirmation: Follow Diagrams, No Mistakes!】
Wire strictly according to the diagram for your purchased series count. Double-check all connections with a multimeter before first power-on!

4S

5S

【Required Skills & Accessories (Do Not Buy Without)】

Basic soldering skill and a multimeter are required. This is a bare board. NO wires, connectors, batteries, or charger are included.

For continuous current > 50A, solder extra copper wires as instructed to reduce heat.

You MUST use a dedicated Lithium Battery Charger! Lead-Acid chargers are PROHIBITED! Their high voltage can permanently damage the BMS, causing protection failure and fire hazard.

【Key Concept Clarification】

“100A” is the instantaneous protection threshold, not continuous current. See specs below for continuous ratings.

Select BMS current rating based on your load's maximum power draw, not battery capacity (Ah).

Specifications

Package Includes

BMS Protection Board x 1

(Note: NO wires, connectors, batteries, or charger are included)