Description
5S 18V/21V 20A Lithium Battery Charging Protection Board – BMS for 5 Series Li-ion Packs
Protect and optimize your 5-cell (5S) lithium-ion battery packs with this 5S 18V/21V 20A Charging Protection Board, a feature-packed Battery Management System (BMS) essential for DIY battery building and power tool applications. This smart module manages charging, discharging, and cell balancing for 18V/21V pack builds—preventing overcharge, over-discharge, overcurrent, and short-circuit events. Its onboard MOSFETs, ICs, and heavy-gauge wiring ensure up to 20A continuous current, making it ideal for e-bike, drone, robotics, or backup power bank stacks.
Clearly labeled solder pads and included pre-wired harness ensure straightforward wiring and installation. Designed for all common 18650/21700/26650/Power tool battery projects.
Key Features
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Suits 5S lithium-ion (18V/21V nominal) battery packs
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Maximum continuous discharge current: 20A
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Cell balancing and equalization circuit for longer pack life
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Advanced IC management for overcharge, over-discharge, and overcurrent protection
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Built-in short-circuit and temperature protection
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Input: 21V DC max charging voltage
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Output: Up to 20A continuous, suitable for power tools, e-bikes, inverter packs
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Pre-wired heavy-duty leads (red, black, yellow, blue)
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Compatible with all standard cylindrical Li-ion cells
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Compact PCB: ~55 x 45 mm (references may vary)
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Easy to integrate for new packs or pack repair
Applications
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Custom lithium battery packs (power tools, e-bikes, solar banks)
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Robotics and RC builds
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DIY energy storage and inverter systems
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Power tool battery pack repair/upgrades