4S 14.8V 16.8V 30A Li-ion 18650 Battery BMS Protection Board

4S 14.8V 16.8V 30A Li-ion 18650 Battery BMS Protection Board is an advanced battery management system engineered to safeguard 4-series lithium-ion and lithium-polymer cell packs. Therefore,, it ensures maximum safety by preventing overcharge, over-discharge, short-circuit, and overcurrent conditions during high-drain operations. Furthermore,, this module incorporates an integrated cell balancing circuit that optimizes individual cell voltages for uniform charging. Consequently,, users can extend overall battery lifespan and reliability in demanding power setups. However,, proper thermal management should be maintained during continuous high-amp draws to prevent overheating.

Key Features:

• Overcharge Protection: Detects and halts charging when cell voltage exceeds safe limits to prevent thermal runaway.
• Over-Discharge Protection: Automatically cuts off the load when cell voltage drops too low, protecting cells from permanent capacity loss.
• Short-Circuit Protection: Instantly reacts to accidental short circuits on the output terminals to safeguard both the load and the battery pack.
• Overcurrent Protection: Monitors continuous discharge output to restrict current spikes beyond safe operational thresholds.
• Balanced Charging: Equalizes individual cell voltages across the 4S pack to guarantee complete and uniform charging cycles.

Technical Specifications:

• Cell Configuration: 4 Series (4S)
• Nominal Voltage: 14.8 V (Compatible with 14.4 V to 16.8 V packs)
• Continuous Working Current: 15 A
• Instantaneous Overcurrent: 20 A to 30 A
• Overcharge Detection Voltage: 4.25 V ± 0.025 V per cell
• Over-Discharge Detection Voltage: 2.50 V ± 0.08 V per cell
• Operating Temperature: -40°C to +85°C

Mechanical Specifications:

• Board Material: High-grade FR4 glass epoxy PCB with copper cladding
• Termination Type: Solder pads for power lines and multi-pin balance connector header
• Cooling Configuration: Open-air board design; optional aluminum heatsink recommended for sustained high-current loads
• Mounting Structure: Compact low-profile rectangular layout designed for shrink-wrap battery pack integration

Dimensions:

• Length: ≈ 50 mm
• Width: ≈ 35 mm
• Thickness: ≈ 3.5 mm
• Weight: ≈ 10 g

Pinout and Wiring:

• B+: Connects to the positive terminal of the 4th (top) battery cell.
• B3: Connects to the junction between the 3rd and 4th battery cells.
• B2: Connects to the junction between the 2nd and 3rd battery cells.
• B1: Connects to the junction between the 1st and 2nd battery cells.
• B-: Connects to the negative terminal of the 1st (bottom) battery cell.
• P+: Shared positive connection for both charging input and discharging output.
• P-: Negative connection for charging input and discharging output.

Datasheet Reference:

• Download 4S 30A BMS Protection Board Datasheet

Commonly Used in:

• Cordless Power Tools: Managing custom high-drain battery packs for portable drills and electric screwdrivers.
• Electric Bicycles: Providing reliable cell balancing and current cutoff for light e-bike conversion packs.
• Backup Power Supplies: Protecting uninterrupted power sources and 14.8V portable instrumentation batteries.

Applications:

• DIY Energy Storage: Assembling custom 18650 battery banks for solar security systems and LED floodlight setups.
• Robotics Power Modules: Safeguarding multi-cell lithium configurations used in heavy-duty robotic platforms and automated guided vehicles.
• E-Scooter Battery Packs: Maintaining pack integrity and preventing cell imbalance during rapid charge and discharge cycles.

Equivalent Models:

• 4S 40A BMS: A higher current capacity variant, although it features a larger physical footprint.
• 3S 30A BMS: A lower voltage alternative configured for 11.1V three-cell setups.
• 4S 20A BMS: A lighter duty protection module designed for lower current draw electronics.

Package Includes:

• 1 × 4S 14.8V 16.8V 30A Li-ion 18650 Battery BMS Protection Board
• 1 x Multi-pin balance wire harness cable