SPIDER Automation | 5S 25A 18650 Lithium-Ion Battery Management System (BMS) | 21V Battery Protection Board
Product Overview
The SPIDER Automation 5S 25A Lithium-Ion Battery Management System (BMS) is a compact battery protection module designed for rechargeable lithium-ion battery packs configured with five cell groups connected in series (5S). It monitors individual cell-group voltage conditions and provides protection functions against overcharging and excessive battery discharge.
Designed for conventional 3.7V nominal 18650 lithium-ion cells, the 5S configuration produces an 18.5V nominal battery pack with a 21V full-charge voltage. The board specifies a maximum charging current of 25A and a discharge current of 25A. Its product description also advertises a peak-current capability of up to 40A for high-current equipment applications.
With a compact PCB footprint of approximately 55 × 19mm, this protection board can be integrated into compatible battery assemblies for electric tools, DC motors, drills and other battery-powered equipment designed around a 5S lithium-ion supply.
Technical Features & Protection Functions
- 5S Lithium-Ion Battery Configuration: Designed for battery packs containing five series-connected lithium-ion cell groups.
- Overcharge Protection: Monitors individual cell voltage and specifies an overcharge detection range of 4.23–4.28V.
- Overcharge Protection Delay: Specified response delay of 0.5–1.5 seconds.
- Over-Discharge Protection: Detects low cell voltage within the specified 2.72–2.88V range.
- Over-Discharge Recovery: Specified recovery voltage range of 2.9–3.1V per cell.
- Charging Capability: Maximum specified charging current of 25A.
- Discharge Capability: Maximum specified discharge current of 25A.
- High-Current Application: The product description advertises up to 40A peak current for high-current equipment.
- Protection Current Parameters: The specification lists 60A for both overcharge and over-discharge protection current.
- Compact PCB Construction: Narrow board format measuring approximately 55 × 19 × 5mm.
Electrical Configuration & Battery Voltage
This BMS is designed for a 5S lithium-ion battery configuration. Five cell groups are connected in series, with the voltage of each group adding together to determine the total battery pack voltage.
| Battery Parameter | Voltage |
|---|---|
| Series Configuration | 5S (5 cell groups in series) |
| Nominal Voltage per Cell | 3.7V |
| Full-Charge Voltage per Cell | 4.2V |
| Total Nominal Pack Voltage | 18.5V |
| Total Full-Charge Pack Voltage | 21V |
Charging requirement: Use a compatible 21V CC/CV lithium-ion charger for a conventional 5S battery pack using 4.2V-per-cell charging. The charger must also be suitable for the battery pack’s charging-current requirements.
Charging & Discharge Current Specifications
The board is specified for high-current battery applications, with separate charging and discharge current ratings. The supplied electrical specifications list 25A charging current and 25A discharge current, while the product description separately advertises a peak-current capability of up to 40A.
- Maximum Specified Charging Current: 25A.
- Maximum Specified Discharge Current: 25A.
- Advertised Peak Current: Up to 40A in the product description.
- Overcharge Protection Current Parameter: 60A as listed in the product specifications.
- Over-Discharge Protection Current Parameter: 60A as listed in the product specifications.
The 40A peak-current statement is distinct from the specified 25A charging and discharging ratings. For system design, use the 25A specified current ratings as the reference and do not treat the 40A peak claim as a continuous operating rating.
Cell Voltage Protection Parameters
The protection circuit uses individual cell-voltage thresholds to identify overcharge and over-discharge conditions. These thresholds are important when selecting compatible cells and designing a 5S lithium-ion battery pack.
| Protection Parameter | Specified Value |
|---|---|
| Single-Cell Overcharge Detection | 4.23–4.28V |
| Overcharge Protection Delay | 0.5–1.5 seconds |
| Single-Cell Over-Discharge Detection | 2.72–2.88V |
| Single-Cell Over-Discharge Recovery | 2.9–3.1V |
Applications
This 5S lithium-ion battery protection board is intended for compatible 18.5V nominal battery packs used in portable and high-current equipment. Potential applications include:
- Electric Drill Battery Packs: Protection circuitry for compatible 5S lithium-ion battery packs used in cordless drills.
- Cordless Electric Tools: Battery protection for suitable portable power tools designed around a 5S battery supply.
- DC Motor Systems: Protection for compatible DC motor applications operating within the board’s specified current ratings.
- Portable Power Equipment: Battery protection for compatible rechargeable equipment using an 18.5V nominal battery pack.
- DIY 18650 Battery Packs: Protection circuitry for custom-built 5S lithium-ion battery assemblies.
- Robotics Projects: Battery protection for mobile robots and compatible robotic platforms.
- Electric Screwdrivers: Integration into suitable cordless screwdriver battery assemblies.
- Workshop Equipment: Protection for compatible portable workshop tools and battery-powered equipment.
- Experimental Motor Projects: Battery protection for electronics development projects using 5S-powered motor systems.
- Custom Battery-Powered Devices: Integration into equipment designed for an 18.5V nominal lithium-ion battery supply.
Package Contents
- 1 × 5S 40A 18650 Lithium-Ion Battery Protection Board
Product Specifications
| Parameter | Specification |
|---|---|
| Product Type | Lithium-Ion Battery Protection Board (BMS) |
| Battery Configuration | 5S (5 series cell groups) |
| Compatible Cell Type | 3.7V nominal lithium-ion cells, including 18650 format |
| Nominal Battery Voltage | 18.5V |
| Full-Charge Battery Voltage | 21V |
| Maximum Specified Charging Current | 25A |
| Maximum Specified Discharge Current | 25A |
| Advertised Peak Current | Up to 40A |
| Single-Cell Overcharge Protection Voltage | 4.23–4.28V |
| Overcharge Protection Delay | 0.5–1.5s |
| Single-Cell Over-Discharge Protection Voltage | 2.72–2.88V |
| Single-Cell Over-Discharge Recovery Voltage | 2.9–3.1V |
| Overcharge Protection Current | 60A |
| Over-Discharge Protection Current | 60A |
| PCB Length | 55mm |
| PCB Width | 19mm |
| PCB Thickness | 5mm |
| Product Weight | Approximately 4g |
Connection & Operating Recommendations
- Correct Battery Configuration: Use this board with a compatible 5S lithium-ion battery pack only.
- Charging Voltage: Use a suitable 21V CC/CV charger designed for conventional 5S lithium-ion batteries.
- Cell Compatibility: Use cells with compatible chemistry, capacity and voltage characteristics. Keep the five series-connected cell groups properly matched.
- Connection Sequence: Follow the actual PCB terminal markings and applicable connection diagram for all battery and load connections.
- Current Selection: Design normal charging and discharge operation around the specified 25A ratings. Do not treat the advertised 40A peak figure as a continuous rating.
- Wiring: Select wires, connectors and insulation suitable for the intended battery current.
- Short-Circuit Prevention: Insulate exposed solder joints and battery terminals to prevent accidental short circuits.
- Mechanical Protection: Secure the PCB inside a suitable battery enclosure and protect it from vibration, conductive debris and physical damage.
- Charger Compatibility: Use a charger specifically designed for a 5S lithium-ion pack; the protection board does not replace a proper CC/CV charger.
