3S 10A BMS Lithium-Ion Battery Protection Board with Cell Balancing (11.1V / 12.6V)

The 3S 10A BMS (Battery Management System) is the standard foundation for anyone looking to build a custom 11.1V lithium-ion battery pack. Designed to manage three lithium cells (18650, 21700, or LiPo) wired in series, this board delivers the perfect balance of moderate current handling and comprehensive safety. Operating at a peak fully-charged voltage of 12.6V, it is the absolute go-to module for replacing heavy lead-acid batteries or powering modern 12V electronics, sensors, and networking gear.

What elevates this specific module above ultra-basic protection boards is its integrated cell balancing feature. Over dozens of charge cycles, individual cells in a series pack will naturally drift in voltage. The onboard balancing circuitry monitors each of the three tiers independently. When one cell hits the 4.2V maximum before the others, the board gently bleeds off that excess voltage through surface-mount resistors, allowing the remaining cells to catch up. This guarantees your entire pack reaches true 100% capacity safely, extending its usable lifespan significantly.

Key Features & Functional Advantages:

• 10A Continuous Discharge: Capable of safely delivering a steady 10 Amps of current (roughly 120 Watts of continuous power), making it ideal for moderate-drain electronics and lighting without overheating.

• Integrated Cell Balancing: Automatically equalizes the voltage across all three cells during the final trickle-charge phase, preventing premature pack degradation and capturing maximum runtime.

• 4-Tier Safety Suite: Features instant automatic hardware cut-offs for over-charge voltage, deep over-discharge voltage (preventing permanent chemistry death), over-current faults, and hard short-circuits.

• Compact Integration: Designed with a slim, flat footprint that easily slips alongside a triangle or flat-pack 18650 cell configuration without wasting valuable enclosure space.

• Common Port / Split Port Wiring: Depending on the specific manufacturer revision, it easily wires into your project to safely regulate both incoming charge voltage and outgoing load current.

Perfect For:

• DIY 12V UPS Systems: The ideal power management brain for building custom backup batteries to keep Wi-Fi routers, homelab network switches, and security cameras online during power outages.

• Custom LED Lighting: Safely regulates power for portable 12V LED floodlights, camping lanterns, and RGB strip lighting arrays.

• Portable Audio Speakers: Provides safe, balanced power to 12V Bluetooth amplifier boards in custom-built boomboxes and desktop speakers.

• Solar IoT & Telemetry: An excellent main power controller for 12V off-grid telemetry nodes, environmental sensors, and remote weather stations.

Technical Specifications:

• Configuration: 3S (3 Cells in Series)

• Supported Chemistry: Lithium-Ion (18650, 21700, etc.) with 3.7V nominal / 4.2V peak rating

• Nominal Voltage: 11.1V

• Full Charge Voltage: 12.6V (Requires a dedicated 12.6V CC/CV lithium charger)

• Maximum Continuous Current: 10A

• Peak / Transient Current: ~20A (Brief spikes)

• Overcharge Protection Threshold: 4.25V ±0.05V per cell

• Over-Discharge Cut-off Threshold: 2.5V ±0.05V per cell

• Balancing Current: ~42mA to 60mA per cell

• Approximate Dimensions: 53 mm x 17 mm x 4 mm

Ensure your order is placed by 2PM to guarantee next-day delivery! Our commitment to prompt service includes a 24-hour delivery system through our network of carriers, aimed at ensuring your package arrives right on schedule.

Please note, a delivery fee of €4.99 applies for orders under €50. For those in remote areas, be aware that our couriers may apply an extra surcharge. This additional fee helps cover the costs of transporting your items to harder-to-reach locations.