JK-QB2A8S-20P

JK-QB2A8S-20P

JK-QB2A8S-20P Active Balancing Lithium Battery BMS Protection Board V19.4.1

3~8S Smart Battery Management System with 2A High Current Active Equalization for Ternary / LiFePO4 / LTO Battery Packs

Product Overview

This JK-QB2A8S-20P intelligent BMS is specially designed for large-capacity series lithium battery packs. It adopts self-developed energy transfer active balancing technology with a maximum continuous balancing current of 2A. This high-current active balancing greatly improves cell consistency, extends battery service life, increases driving range and slows down cell degradation.

The protection board comes with built-in Bluetooth module, compatible with iOS and Android JK-BMS APP. Users can connect the board via Bluetooth to view real-time battery data, adjust all working parameters and control charge/discharge switches remotely. It is widely applied to mobility scooters, sightseeing vehicles, shared low-speed cars, high-power energy storage, solar power stations and base station backup power supplies.

Core Functional Features

2A High Current Active Balancing

Automatically transfer energy from high-voltage cells to low-voltage cells when voltage difference exceeds the preset threshold

Comprehensive Multi-Layer Safety Protection

Overcharge, over-discharge, over-current, short-circuit, over-temperature and low-temperature full protection

Standard Built-in Heating System

Support forced heating startup to activate batteries in cold weather areas

Bluetooth APP Full Control

Real-time monitoring of voltage, current, temperature and SOC; customizable all protection parameters

Optional Multi Communication Interfaces

Optional CAN, RS485 and UART GPS port, matched with dedicated display screen

30-Minute Emergency Discharge Mode

Temporarily unlock charge and discharge to avoid sudden breakdown on the road

Battery Compatibility & Model Options

  • Ternary Lithium Battery: 3S ~ 8S
  • Lithium Iron Phosphate (LiFePO4): 3S ~ 8S
  • Lithium Titanate (LTO): 7S ~ 8S

Optional versions: Standard model, CAN communication model, RS485 communication model, CAN+RS485 dual communication integrated model

Main Technical Specifications

Item Parameter Value Unit
Supply Voltage 7.5 ~ 40 V
Max Balancing Current 2 A
Max Continuous Charge Current 200 A
Max Continuous Discharge Current 200 A
Max Instantaneous Peak Current 400 A
Operating Temperature Range -30 ~ 70 ℃
Product Dimensions 227*120*21.76 mm
Net Weight 662 g

Full Protection List

  • Charge Overvoltage Protection & Auto Recovery
  • Discharge Undervoltage Protection & Auto Recovery
  • Charge Overcurrent Protection & Delay Reset
  • Discharge Overcurrent Protection & Delay Reset
  • Charge & Discharge Over-Temperature Protection
  • Low Temperature Charging Protection
  • Instant Short Circuit Protection
  • MOS Tube Overheat Protection
  • Discharge Pre-charge Anti-Impact Function
  • Intelligent Low Power Sleep Mode

Application Scenarios

This BMS is suitable for electric mobility scooters, small sightseeing vehicles, shared low-speed EVs, household energy storage systems, off-grid solar power stations, communication base station backup power, RV lithium battery packs and large portable energy storage equipment.

Operation Guide

  1. Check all balance wires, temperature sensors and power terminals before power on to avoid short-circuit damage.
  2. Three activation methods: Charger activation, external key switch activation and optional display screen activation.
  3. Scan the QR code on the product to download the official JK-BMS App, compatible with Android 7.0 and all iOS versions.
  4. Select matching battery type (Ternary / LiFePO4 / LTO) and set cell strings, battery capacity and protection thresholds in the App.
  5. Adjust balance trigger voltage difference, charge and discharge current limits according to your actual battery pack configuration.

Important Notes

  • This BMS only supports 3~8 series lithium battery packs, do not match mismatched cell strings.
  • It is recommended to install a temperature control switch in the heating circuit to prevent thermal runaway under extreme conditions.
  • Do not operate continuously exceeding the rated maximum charge and discharge current to extend service life.
  • If you need CAN, RS485, alarm or fan control functions, select the corresponding extended version before ordering.

Download Official Manuals & JK-BMS App

Visit Download Center
Back to blog