Description
This 3S 25A BMS (Battery Management System) Protection Board is specifically designed for 3-series 18650 lithium battery packs (11.1V nominal, 12.6V full charge). It provides advanced protection features including overcharge, over-discharge, short-circuit, and balance protection, ensuring extended battery life and safety during charging and discharging cycles.
With support for continuous 25A current and up to 40A peak discharge, this BMS is ideal for high-power applications like DIY battery packs, e-bikes, power banks, solar storage, LED systems, and portable electronics.
Equipped with cell balancing, the module maintains voltage consistency across all 3 cells, improving lifespan and performance of the battery pack.
✅ Key Features
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⚡ For 3S Lithium Battery Packs (11.1V nominal, 12.6V max)
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25A Continuous Charge/Discharge Current
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Peak Discharge Current: Up to 35–40A
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⚙️ Overcharge, Over-discharge, and Short Circuit Protection
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Automatic Recovery from short circuits
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Cell Balancing Feature: Ensures even voltage across all 3 cells
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️ Operating Temp: -40°C to +50°C
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Compact and Easy to Integrate
Technical Specifications
| Parameter | Specification |
|---|---|
| Battery Type | 3S 18650 Li-ion / Lithium polymer |
| Nominal Voltage | 11.1V |
| Max Charging Voltage | 12.6V (CC/CV) |
| Single Cell Balance Voltage | 4.2V |
| Continuous Current | 25A |
| Peak Current (Instantaneous) | 35A–40A |
| Overcharge Protection | 4.25–4.35V ± 0.05V per cell |
| Over-discharge Protection | 2.3–2.7V ± 0.05V per cell |
| Balance Current | 40–50 mA |
| Quiescent Current | <30 µA |
| Internal Resistance | <100 mΩ |
| Short Circuit Protection | Yes, with delay and self-recovery |
| Effective Life | >30,000 hours |
| Storage Temp | -40°C to +80°C |
Applications
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18650 Lithium battery pack DIY projects
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Solar power storage systems
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12V backup battery systems
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Electric scooters, bikes, and e-skateboards
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RC cars, drones, and power tools
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LED lighting systems
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Power banks and UPS systems
FAQ – Frequently Asked Questions
Q1: Can I use this BMS for 3 AA or AAA rechargeable batteries?
No. This BMS is designed specifically for lithium-ion 18650 cells, not NiMH or alkaline batteries.
Q2: Will this work with 3S LiFePO4 batteries?
⚠️ No. LiFePO4 cells have a different charge/discharge profile. This is meant for Li-ion/Li-polymer only.
Q3: Does this board balance the cells automatically?
✅ Yes. It includes active balancing to keep cells within optimal voltage range.
Q4: Can it handle high-current applications like e-bike motors?
✅ Yes, up to 25A continuous and 40A burst, but ensure proper wiring and cooling for safety.
Q5: What happens during a short circuit?
⚠️ The board will trigger short-circuit protection and automatically recover after a brief delay.
