JK-BxAxxS-15P / 20P High Current Active Balancing BMS Manual V19.1.1
1. Product Overview
1.1 Core Advantages
This BMS is specially developed for large-capacity series lithium battery packs, compatible with ternary lithium, LiFePO4, lithium titanate cells. It adopts self-developed energy transfer active balancing technology, supporting 1A / 2A large balancing current, which greatly improves cell consistency, extends cycle life and driving range.
Built-in Bluetooth module, matched with iOS & Android Jikong BMS APP. Users can monitor real-time battery data, adjust protection parameters, control charge/discharge remotely via mobile phone. Widely applied to energy storage, RV, golf carts, low-speed EV, base backup power, solar off-grid systems.
1.2 Full Standard & Optional Functions
- Standard: Bluetooth, UART, LCD display port, full set of charge/discharge protection (OV/UV/OC/short-circuit/high-low temp), intelligent sleep, emergency 30min power supply
- Optional add-ons: CAN / RS485 communication, heating module, buzzer alarm, battery parallel, ACC ignition detection, GPS positioning
- Hardware: ±3mV high precision voltage sampling, independent NTC temperature sensors, built-in coulomb counter for SOC calculation
2. Model Selection Guide
2.1 Basic Function Configuration Table
| No. | Function Item | Specification |
|---|---|---|
| 1 | Active Balancing Current | 1A / 2A selectable |
| 2 | Bluetooth / UART / Display Port | Standard Equipped |
| 3 | Temperature Sensor | 1 built-in + 2 external NTC |
| 4 | CAN / RS485 / Heating / Alarm / Parallel / ACC | Optional Upgrade |
| 5 | Overcharge / Overdischarge / Short Circuit Protection | Standard Equipped |
2.2 Cell Compatibility Table
| Model | Ternary | LiFePO4 | LTO Lithium Titanate |
|---|---|---|---|
| JK-BxA20S-15P/20P | 7~20S | 8~20S | 14~20S |
| JK-BxA24S-15P/20P | 7~24S | 8~24S | 14~24S |
Suffix Rule Explanation:
- -15P: Max continuous 150A charge & discharge, peak 300A
- -20P: Max continuous 200A charge & discharge, peak 400A
- B1A = 1A balance; B2A = 2A balance; C=CAN, R=RS485, H=Heating
3. Main Electrical Specifications
| Parameter | 150A Version | 200A Version | Unit |
|---|---|---|---|
| Working Voltage | 20 ~ 100 | 20 ~ 100 | V |
| Static Power Consumption | ≤800 | ≤800 | mW |
| Operating Temp | -30 ~ 70 | -30 ~ 70 | ℃ |
| Max Balance Current | 1 / 2 | 2 | A |
| Continuous Charge/Discharge | 150 | 200 | A |
| Peak Instant Current | 300 | 400 | A |
| Internal Loop Resistance | 0.365 | 0.275 | mΩ |
| Overall Dimension | 162*102*20.4 | 162*102*20.4 | mm |
| Net Weight | 560 | 560 | g |
Factory Default Voltage Parameters
Pre-set protection thresholds for ternary / LFP / LTO cells, adjustable inside Jikong APP:
- Balance trigger voltage difference: 0.01V auto start equalization
- Overcharge / undervoltage / auto shutdown voltage matched to different battery chemistries
- Overcurrent, short-circuit, high & low temperature protection delay preset
4 Interface & Wiring Introduction
Main Connector Functions
- P1/P2: Cell sampling wires B1~B24, battery total negative B-
- P3: Dual NTC temperature sensor ports
- P4: Multiplex CAN & RS485 communication port
- P5: UART port for external 4G/GPS module
- P6: Special LCD display screen interface
- P7: Multi battery pack parallel control signal port
- P8: Buzzer alarm module port
- P9: ACC ignition & charger detection port
- D1: Heating wire terminal; P-: Load/charger negative terminal
Important Wiring Notice:
- Connect all balance wires before power on, wrong wiring will burn MOS tubes
- B- (battery negative) and P- (load negative) cannot be reversed
- 7~20S packs leave redundant sampling pins empty; 21~24S must connect all B1-B24 lines
5 Core Function Operation Guide
5.1 Active Balancing (1A/2A High Current)
The BMS transfers energy from high-voltage cells to low-voltage cells automatically. Users set battery type, rated capacity, balance voltage gap via mobile APP. Max balance current 2A, recommended ≤0.2C of battery capacity, can be manually turned off if not needed.
5.2 Optional Functional Modules
- Heating Module: 10A heating current, prevent low-temperature charging failure; match 45~65℃ normally closed thermal fuse for secondary safety protection
- ACC Detection: Two trigger modes (12~100V voltage input or short ACC pins); C_Detect port wake up charging when plugging charger
- Battery Parallel: Use with dedicated parallel module, turn off charge current limit in APP for large energy storage system
- Emergency Mode: After triggering overheat / overdischarge / cell loss fault, enable emergency mode to keep charge & discharge for continuous 30 minutes to avoid vehicle breakdown
- Auto Sleep: Enter low-power standby if charge/discharge current below 1A for 26 hours; wake by charger or physical button
5.3 Full Protection Logic
All protection items (overcharge, overdischarge, charge/discharge overcurrent, short circuit, high/low temperature) will cut off power automatically and recover after parameters back to safe range, all delay time editable in APP.
6 Jikong BMS Mobile APP Operation
6.1 APP Download & System Requirement
Scan QR code on product package to download, support Android 7.0 & above / all iOS versions.
6.2 Three BMS Activation Methods
- Charger activation: charger output voltage 2V higher than battery pack
- Physical button wake-up (with optional screen kit)
- LCD screen plug-in activation
6.3 Parameter Setting Steps
1. Bluetooth connect BMS device 2. Select battery chemistry (LFP / Ternary / LTO) 3. Set cell count, battery capacity, all protection voltage/current thresholds 4. Save settings, parameters take effect immediately
Application Scenarios
- Off-grid & household commercial energy storage systems
- RV, camper, golf cart, low-speed mobility vehicles
- Shared electric vehicles, forklifts
- Communication base station backup power
- Large series-parallel lithium battery energy storage packs