Product Overview
The YKN BMS4S is a protection board specifically designed for 4 series lithium iron phosphate battery packs. It is suitable for small energy storage batteries, solar street lights, 12V lithium batteries, and similar applications. The board uses an integrated intelligent lithium battery management chip and supports RS485, CAN, and Bluetooth communication. Key parameters can be flexibly adjusted through an upper computer application based on customer requirements.

Supported Battery Configuration
This BMS supports 4 series LiFePO4 cell configurations only. The charging voltage is 14.6V with a cell voltage range of 9.6V to 15V. Both charge and discharge are configured as same port, simplifying wiring.

Current Ratings
Continuous charging current is up to 150 amps. Continuous discharging current is also up to 150 amps. This makes the BMS suitable for high power 12V battery packs used in inverters, trolling motors, and energy storage systems.

Power Consumption
Running consumption is ≤25 milliamps. Sleep consumption is very low at ≤300 microamps. When the BMS is in a stationary state with no activity, it enters sleep mode to reduce power draw, preserving battery capacity during storage.

Protection Functions
The BMS integrates hardware protection functions including overvoltage protection, undervoltage (low voltage) protection, overcurrent protection, high temperature protection, low temperature protection, and short circuit protection. These protections are handled directly by the hardware for fast response without software delay.

Intelligent Balancing
The board includes an intelligent balancing function. The user can set the starting voltage and starting voltage difference for balancing via the upper computer. Balancing can be configured as charging balancing (active only during charging) or static balancing (active even when idle). This helps maintain cell voltage uniformity and extends pack life.

Temperature Monitoring
The BMS supports 4 way battery cell temperature detection using external NTC thermistors. It also includes 1 way power temperature detection to monitor the board itself. This comprehensive temperature sensing allows precise thermal management and protection.

Communication Options
Multiple communication interfaces are available. Bluetooth enables wireless monitoring and configuration from a smartphone app. RS485 supports wired connection to inverters, displays, or remote monitoring systems. CAN bus allows integration with industrial battery management networks. All parameters can be read and adjusted via the upper computer.

Additional Functions
Reserved heating function allows connection of an external heating pad to warm cells in cold environments before charging. Reserved buzzer function can provide audible alarms for fault conditions. The BMS supports series and parallel connection of multiple battery packs for larger capacity or higher voltage systems.

Physical Specifications
Dimensions are 160 millimeters length, 95 millimeters width, and 25 millimeters height. Operating temperature range is -30°C to 75°C, suitable for outdoor and industrial environments.

Applications
This BMS is ideal for small home energy storage batteries paired with solar panels. It protects 12V LiFePO4 batteries used in RVs, campervans, and marine house banks. It works for solar street light batteries, off grid lighting systems, and portable power stations. The 150A rating also suits electric trolling motors, floor cleaning machines, and small electric vehicles.