3S 12V 25A 18650 Lithium Battery Protection Board

3S 12V 25A 18650 Lithium Battery Protection Board (BMS) protects 3-cell 18650 packs with reliable overcharge, overdischarge, short-circuit, and overcurrent control. Integrate it to drive 12 V loads safely while you maintain pack health and cycle life.

Key Features:

• 3S Protection: Manages 3 series cells for nominal 11.1 V systems.
• 25 A Continuous Discharge: Supports medium-power tools, LED lighting, and DC motors.
• Multi-Level Safety: Overcharge, overdischarge, short-circuit, and overcurrent protection.
• Cell Balancing: Passive balancing equalizes cell voltage near full charge.
• Low Standby Drain: Minimizes self-consumption for longer shelf life.
• Thermal Safeguards: NTC input on many variants enables temperature cut-off.

Technical Specifications:

• Battery Configuration: 3S 18650 Li-ion/Li-polymer
• Nominal Pack Voltage: 11.1 V (10.8–11.1 V typical)
• Max Charge Voltage: 12.6 V (4.2 V per cell)
• Continuous Discharge Current: 25 A
• Recommended Continuous Charge Current: up to 10–12 A (model dependent)
• Overcharge Protection: ~4.25 ± 0.05 V per cell, auto-release near 4.15–4.20 V
• Overdischarge Protection: ~2.7–2.9 V per cell, auto-release after recharge above ~3.0 V
• Overcurrent / Short-Circuit Cutoff: Trip typically 50–80 A with fast response
• Balancing Type: Passive bleed, ~30–60 mA near 4.2 V
• Quiescent Current: Typically < 50 µA (pack idle)
• Operating Temperature: −20 °C to +60 °C (load), −0 °C to +45 °C (charge)

Mechanical Specifications:

• Board Material: FR-4 PCB with copper pours for high current
• Power Devices: Low R_DS(on) MOSFETs with thermal vias
• Connectors/Pads: Large solder pads for B-, B+, P-, P+ and sense leads
• Mounting: 2–4 mounting holes; standoff compatible

Dimensions:

• Board Size: Approx. 45–65 mm (L) × 20–35 mm (W) × 3–6 mm (H) by vendor
• Hole Pitch: Varies by batch; confirm with product photos or drawing
• Pad Gauge: Size supports 14–18 AWG wiring for 25 A paths

Pinout and Wiring:

• B-: Pack negative (connect to cell 1 negative)
• B1: Junction between cell 1 and cell 2
• B2: Junction between cell 2 and cell 3
• B+: Pack positive (cell 3 positive)
• P-: Load/charger negative
• P+: Load/charger positive (same node as B+ on most boards)
• NTC (if present): Attach the temperature probe to the pack for thermal cut-off
• Wire the cells in series as B- → B1 → B2 → B+. Connect charger and load to P+ / P-. Observe polarity and insulate all joints.

Datasheet Reference:

• Refer to the seller’s schematic and mechanical drawing for exact pad layout, thresholds, and balancing current for this 3S 25 A model.
• Search “3S 25A BMS 18650 datasheet” to review controller IC specs, timing, and protection flow.

Applications:

• DIY 12 V Battery Packs: Build protected packs for portable electronics and lighting.
• LED Lighting and Inverters: Drive 12 V strips and small inverters safely.
• RC and Robotics: Power motors and controllers with reliable cutoff behavior.
• Solar Storage: Pair with MPPT/CC/CV chargers for small off-grid systems.
• UPS and Backup: Protect 3S packs in compact backup supplies.

Equivalent Models:

• 3S 20A BMS Boards: Lower current substitutes for lighter loads.
• 3S 30A BMS Boards: Higher margin options for surge-heavy applications.
• Daly/JBD/Generic 3S BMS: Comparable protection with varying balancing current and connectors.

Package Includes:

• 1 × 3S 12V 25A 18650 Lithium Battery Protection Board