Overview: 4S 16.8V 40A Li-Ion Cell BMSThe 4S 16.8V 40A Li-Ion Cell BMS Charging Protection Module is a compact Battery Management System engineered for 4-cell (4S) lithium-ion and lithium-polymer packs. Designed for medium to high power projects, this BMS provides reliable protection, cell balancing, and automatic recovery to keep your pack safe and performing at its best.Key SpecificationsPack configuration: 4S (up to 16.8V fully charged)Continuous discharge current: 40APeak cutoff current: approximately 50 to 55AOvercharge cutoff: ~4.25 ±0.05V per cellOver-discharge cutoff: ~2.7 ±0.1V per cellOperating temperature: -20°C to 60°CCompatibility: works with CC/CV Li-Ion chargersProtections and How They WorkOvercharge protection: Stops charging when any cell exceeds about 4.25V to prevent cell damage.Over-discharge protection: Cuts output when cell voltage drops below about 2.7V to protect cell longevity.Overcurrent protection: Detects high discharge currents and shuts down output if peak currents reach roughly 50 to 55A.Short-circuit protection: Instant cutoff to prevent catastrophic failure of the battery pack or load.Cell balancing: Passive balancing maintains equal voltages across all four cells for improved capacity utilization and longer service life.Automatic recovery: The module can resume normal operation automatically once fault conditions clear, without manual reset in most cases.ApplicationsThis BMS is suitable for a wide range of projects that require a reliable 4S protection solution:DIY 16.8V battery packs and replacement packsElectric bikes, scooters, and personal mobility devicesRobotics, automation, and high-drain actuatorsSolar energy storage and off-grid power systemsHigh-power LED lighting and portable power stationsInverters and UPS systemsInstallation, Compatibility and Best PracticesUse with CC/CV Li-Ion chargers and ensure correct connection to B-, P-, and B terminals as per pack wiring diagram.Ensure proper wiring gauge for 40A continuous loads to avoid voltage drop and heating; consider heavier gauge for peak currents.Mount on a stable, non-conductive surface and provide ventilation when used in enclosed spaces or high ambient temperature.Balance your cells when assembling packs and periodically check cell voltages to ensure effective balancing operation.Why Choose This 4S 40A BMSReliable protection suite for safe charging and discharging cycles.Integrated cell balancing extends battery life and stabilizes pack performance.Robust PCB and thermal design for medium to high power projects.Automatic fault recovery reduces downtime for many common faults.Ideal for makers, engineers, and system integrators building 16.8V battery solutions.Note: Images are for illustration purposes only. Category: BMS Modules and Accessories College Road Electronics4.85 (317 Reviews)
