JKBMS B2A25SRP 7S-25S Active Balance Smart BMS 2A Split Port w/ Bluetooth RS485/CAN for LiFePO4

Overview

The JKBMS B2A25SRP is an active balance smart BMS for lithium battery packs (Li-ion / LiFePO4 / LTO). It supports a 7S to 25S battery string range (chemistry-dependent), built-in Bluetooth for Android/iOS monitoring, and split-port wiring output. The battery pack is self-powered, and charge/discharge current is controlled via an external relay (“Need Relay”).

Key Features

• Active balancing: 2000 mA (2 A), Active Balance (Full State On)
• Battery strings supported:
  • Li-ion: 7S-25S
  • LiFePO4: 8S-25S
  • LTO: 12S-25S
• Wiring output: Split Port
• Power supply mode: Battery pack self-powered
• Cell voltage sensing: single cell voltage detection range 0-5 V; single cell voltage range 1-5 V; voltage acquisition accuracy ±5 mV; typical error <5 mV, error <10 mV over full operating range
• Total voltage detection: 0-100 V, <0.5% FSR (FSR = full scale)
• Current sensing (shunt): -150 A to 300 A, error <0.5% FSR
• Protections/functions listed: short circuit protection; over temperature protection; coulomb counter; support single cell voltage dropout detection
• Bluetooth: built-in; supports Android / iOS phone (use the specified Bluetooth application; search the relevant serial number to view data)
• Communications: RS485/CANBUS (default); CANBUS/HEAT (customized)
• Adjustable settings (as listed):
  • Over charge protection voltage: 1.2-4.35 V adjustable
  • Over charge release voltage: 1.2-4.35 V adjustable
  • Over discharge protection voltage: 1.2-4.35 V adjustable
  • Over discharge release voltage: 1.2-4.35 V adjustable
  • Over current detect delay: 2-120 S adjustable
  • Over charge protection current (ADJ): 10-1000 A
• Operating power consumption: <5 mA (without communication) / 15 mA (485/CAN)
• Standby power consumption: <2 mA
• SoC / capacity estimation: SoC estimation accuracy error <8% (operating conditions); battery remaining capacity error range <8%
• Total cycle AH rule (as stated): cumulative value is half of the charge/discharge value
• Temperature ranges (as listed):
  • Temperature detection: -40 to 1256C
  • Operating temperature: -40 to 856C
  • Storing temperature: -40 to 956C
• Temperature sensors: 3 pcs
• Six security protection (as listed): over charge protection; short circuit protection; over discharge protection; over current protection; all-in protection (cable drop/poor contact); over temp protection

Specifications

Interface/Pin Labels (from labeled diagram)

• CANBUS (need customization): GND, CAN_H, CAN_L
• RS485 (by default): GND, RX, TX, VCC
• LCD (by default): K-, K+, GND, B, A, VCC
• Heat Function (need customization): (connector labeled “Heat Function”)

Smart Working Mode Switching (as described)

• Storage Mode: in transportation/storage/offline or wireless transmission off mode, the BMS is in storage mode and does not consume battery pack current.
• Normal Working Mode: when the charger is inserted in storage/off mode, the BMS returns immediately to normal working mode and protection/equalization/communication functions return to normal.
• Standby Mode: when the pack is static (no charge/discharge current and no equilibrium current), the BMS automatically enters standby after the set time (1-30 days can be set).
• Shutdown: the BMS has an automatic shutdown voltage and automatically shuts down when a cell falls below the shutdown voltage.

Notes

This BMS is specified as “Need Relay” for continuous charge/discharge current control. For selection help and installation guidance, contact support at https://tsolar.top/ or email service@tsolar.top.

Some provided images include additional JK BMS model labels and accessory drawings (e.g., shunt dimension sketches and cable/NTC length callouts). Only the specifications listed above are used for the B2A25SRP where explicitly stated.

Details

Includes the BMS unit plus a shunt, wiring harness, and temperature lead; enclosure size is listed for fit checks before installation.

Other variants in the JK Smart Active Balance series are available for different string counts and balancing current needs.

Choose the model that matches your pack’s series count and communications requirements (RS485/CAN options depend on version).

A compact, enclosed design with internal connectors and electronics arranged for a clean, serviceable wiring layout.

Connector labels help with wiring CAN/RS485 and optional accessories such as an LCD or heating function (where supported).

Built-in Bluetooth monitoring displays pack voltage, current, balance activity, and individual cell readings in the mobile app.

App menus cover device scanning, basic settings, and a full cell-by-cell dashboard for quick health checks.

Multiple protection features are provided, including over/under-voltage, over-current, short-circuit, poor-contact, and over-temp safeguards.

Energy modes support storage/standby behavior and automatic shutdown logic to reduce battery drain during long idle periods.

A quick comparison chart helps confirm the correct model by string range, balancing current, interface type, and physical size.