5S 18.5V 21V 15A 18650 Lithium Battery BMS Protection Board with Cable

5S 18.5V 21V 15A 18650 Lithium Battery BMS Protection Board with Cable is a 5-series (5S 18V/18.5V nominal, 21.0V full charge) lithium-ion Battery Management System (BMS) module supplied complete with a plug-and-play multi-pin cell sense wire harness. Engineered for 5-cell 18V/21V cordless power tool packs, portable vacuum cleaners, and 18.5V solar storage batteries, it delivers 15A continuous discharge current (25A–30A peak) with precision per-cell overcharge (4.22V), over-discharge (2.70V), overcurrent, and short-circuit protection.

Key Features:

• 5S (18.5V Nominal / 21V Max) Power Tool Voltage Standard: Manages 5 series-connected 3.7V 18650/21700 cells (`5 × 3.7V = 18.5V` nominal, `5 × 4.2V = 21.0V` full charge).
• Includes Plug-and-Play Cell Sense Cable Harness: Detachable multi-wire balance connector allows you to solder the sense leads to your 5S cell pack safely before plugging into the BMS board.
• 15A Continuous Discharge Capacity: Low-resistance power MOSFET bank supports 15A continuous working current (~300W at 20V) and up to 25A–30A instantaneous surge current.
• Full 4-Stage Cell Protection: Monitors all 5 cell groups independently to cut off overcharging at 4.22V/cell, over-discharging at 2.70V/cell, overcurrent faults, and output short circuits.
• Low Self-Consumption (≤30µA): Ultra-low quiescent current preserves battery pack charge over months of storage.

Technical Specifications:

• Supported Battery Configuration: 5S (5 Series 3.7V Li-ion / 18650 / 21700 Cells — 18V/18.5V Nominal)
• Charging Voltage: 21.0V DC CC/CV
• Continuous Discharge Current: 15A Max
• Instantaneous Peak Current: 25A to 30A
• Overcharge Detection Voltage: 4.22V ± 0.04V per cell (Release: 4.10V ± 0.05V)
• Over-Discharge Detection Voltage: 2.70V ± 0.08V per cell (Release: 3.00V ± 0.10V)
• Quiescent Current: ≤ 30 µA
• Operating Temperature Range: -40°C to +85°C

Mechanical Specifications:

• PCB Material: FR-4 Double-Sided High-Copper Fiberglass Board
• Interfaces: Heavy-Current `B-` / `P-` / `B+`(`P+`) Solder Pads + Multi-Pin Balance Connector with Wire Harness

Dimensions:

• Length: ~60 mm
• Width: ~42 mm
• Thickness: ~4 mm
• Weight: ~16 g (including cable harness)

Pinout and Wiring:

• B-: Solder thick wire (14–16 AWG) to Cell 1 Negative (Pack Negative 0V).
• P-: Solder thick wire to Load / Charger Negative (-).
• B+ / P+: Shared Pack Positive (21V) — connect to Cell 5 Positive and Load / Charger Positive (+).
• Sense Wire Harness (`B-` → `B1` → `B2` → `B3` → `B4` → `B+`): Solder the sense wires in sequential order from Cell 1 Negative up to Cell 5 Positive, verify rising voltages with a multimeter (`0V, 3.7V, 7.4V, 11.1V, 14.8V, 18.5V`), and then plug the harness into the BMS socket.

Datasheet Reference:

• Protection Architecture: 5-Series Li-Ion Hardware Supervisor IC + Parallel N-Channel Power MOSFET Array

Commonly Used in:

• 18V / 20V Max / 21V Cordless Drill, Impact Driver, and Wrench Packs
• 18.5V Cordless Handheld Vacuum Cleaners and Leaf Blowers
• 5S1P / 5S2P 18650 Portable Power Stations
• 20V Robotics & Industrial Portable Equipment

Applications:

• Rebuilds or custom-assembles 5S (18V/21V) 18650 battery packs for cordless drills, Garden sprayers, and handheld vacuums.
• Simplifies pack assembly and maintenance with its detachable plug-in cell sense harness.
• Pairs with a 5S 18.5V Li-ion balancer board (`PID 3361`) when building high-cycle 5S2P/5S3P packs.

Equivalent Models:

• 5S 18.5V 15A Li-Ion Lithium Battery Protection Board: Direct solder-pad 5S 15A BMS board without the plug-in wire harness.
• 4 Series 30A 18650 Lithium Battery Protection Board 14.8V 16V with Cable: 4-cell (14.8V/16.8V) 30A BMS board with sense cable harness.

Package Includes:

• 1 × 5S 18.5V 21V 15A 18650 Lithium Battery BMS Protection Board with Cable