BattPulse

Securing the Energy Transformation

Leader Battery Management System

Product Technical Datasheet

6S–126S Passive Balancing CAN + WiFi Up to 400 A

Complete technical specifications, electrical data, connector pinouts,
communication interfaces, and ordering information.

Document: BP-BMS-003-DS | Revision 1.0 | March 2026
© 2026 BattPulse by SONAL | info@battpulse.com | battpulse.com

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Product Overview
Key Features
Electrical Specifications
Measurement & Protection
Communication Interfaces
Digital Inputs & Outputs
Connectors & Pinouts
Mechanical & Environmental
Daisy-Chain & High-Voltage Packs
Ecosystem & Compatibility
Ordering Information
Document Revision History

1. Product Overview

The BattPulse Leader BMS is a professional-grade battery management system designed for EV conversions, energy storage systems, e–bike/e–boat builds, and industrial battery packs. It features a high-accuracy 16-bit analogue front-end for per-cell voltage monitoring, a high-precision shunt-based current sensor, passive cell balancing, and communication interfaces (CAN Bus + WiFi+ USB+ RS485).

The system supports 6S to 126S lithium configurations through a scalable daisy–chain architecture and is compatible with multiple lithium chemistries. All connectors use the automotive-grade Molex Micro-Fit 3.0 locking system for reliable, vibration-resistant connections.

Target Applications

EV conversions • E-bike & e-boat battery packs • Solar / ESS battery banks • Industrial battery systems • Custom HV packs (400 V / 800 V via daisy-chain) • OEM integration projects

2. Key Features

Category	Feature
Cell Monitoring	16-bit high-accuracy analogue front-end; per-cell voltage measurement (6–126S)
Cell Balancing	Passive balancing, up to 1 A per cell
Current Sensing	High-precision external shunt-based sensor; up to 400 A continuous
Temperature	Up to 8 external NTC probes (100K 3950); on-board temperature sensor
Protection	Overvoltage, undervoltage, overcurrent, overtemperature, short-circuit
Communication	CAN 2.0B (250 / 500 / 1000 kbps) + WiFi (HTTP/JSON) + USB + RS485
Contactor Control	3 × digital outputs (negative-side switching MOSFETs)
Digital Inputs	3 × galvanically isolated inputs (24–70 V DC; AC 230 V detect)
Scalability	Daisy-chain up to 15 slave units for 400 V / 800 V packs
Connectors	Molex Micro-Fit 3.0 locking, automotive-grade throughout
On-board Display	Integrated OLED for local status and diagnostics
Diagnostics	USB port for serial console and firmware updates
Chemistry Support	Li-ion, LiFePO4 (LFP), Li-NMC, Li-NCA, LTO
Configuration	Web-based settings interface over WiFi; configurable thresholds

3. Electrical Specifications

General Electrical Data

Parameter	Value	Notes
Cell Count (single unit)	6S–16S	Configurable
Cell Count (with daisy-chain)	6S–126S	Up to 15 slave units
Supported Chemistry	Li-ion, LiFePO4 (LFP), Li-NMC, Li-NCA, LTO
Operating Pack Voltage (single unit)	12–67.2 V	Depends on chemistry & cell count
Operating Pack Voltage (daisy-chain)	Up to 800 V	System-level
Continuous Current Rating	Up to 400 A	Shunt-dependent
Quiescent Current	< 15 mA	Idle, WiFi off
Power Supply	Battery-powered	Via Sense & Balance connector

Cell Voltage Measurement

Parameter	Value	Notes
Resolution	16-bit	High-accuracy analogue front-end
Measurement Range	0–5.0 V per cell	—
Accuracy	± 2 mV typical	At 25 °C
Sample Rate	10 Hz (all cells)	100 ms cycle
Channels (single unit)	6–16	Configurable

Current Measurement

Parameter	Value	Notes
Sensor Type	External shunt	High-precision shunt-based
Measurement Range	−500 to +500 A	Bidirectional
Continuous Rating	Up to 400 A	Shunt-dependent
Interface	I²C (via Shunt & CAN connector)	Pins 1–3, 6
Calibration	Software-adjustable	Via web settings

Temperature Measurement

Parameter	Value	Notes
External Probes	Up to 8	NTC 100K 3950
On-board Sensor	1	Board temperature
Measurement Range	−50 to +150 °C	—
Probe Connector	Micro-Fit 3.0 (10-pin)	43025-1000
Probe Count	Configurable (0–8)	Set in BMS settings

Cell Balancing

Parameter	Value	Notes
Method	Passive (resistive)	—
Balancing Current	Up to 1 A per cell	—
Activation	Automatic	Based on cell-voltage delta
Heat Dissipation	On-board	No external components required

4. Measurement & Protection

Protection Thresholds (Configurable via Web Interface)

Protection	Default Range	Action
Overvoltage (OV)	Configurable per chemistry	Disable charge contactor (DO1); set fault flag
Undervoltage (UV)	Configurable per chemistry	Disable discharge contactor (DO2); set fault flag
Overcurrent (OC)	Configurable	Disable contactors; set fault flag
Overtemperature (OT)	Configurable	Disable contactors; set fault flag
Undertemperature	Configurable	Disable charge in cold conditions
Short Circuit	Hardware-level	Immediate shutdown

Fault Reporting

Interface	Fault Data
CAN Bus	Frame `0x370` — fault/warning bitmask (OV, UV, OT, POWERDOWN)
WiFi JSON	`status.event` field — coded integer (0=Normal, 1=Warning, 2=Fault, 3=Critical)
On-board OLED	Visual fault indicator and status text
Contactor Outputs	Automatic contactor disable on fault

5. Communication Interfaces

CAN Bus

Primary telemetry and command interface

Parameter	Value
Standard	CAN 2.0B (11-bit standard identifiers)
Baud Rate	250 / 500 / 1000 kbps (configurable; default 500 kbps)
Byte Order	Little-endian (LSB first)
Transceiver	Automotive-grade CAN transceiver (3.3 V logic)
Termination	On-board 120 Ω; 120 Ω required at each bus end
Cycle Time	100 ms (all frames, 10 Hz)
TX Frames	Pack status, cell voltages, temperatures, I/O states, faults
RX Frames	Command frame (restart, with safety key)
Connector	Shared with Shunt on 6-pin Micro-Fit 3.0 (CAN-H: pin 4, CAN-L: pin 5)

WiFi

HTTP/JSON telemetry interface

Parameter	Value
Standard	802.11 b/g/n (2.4 GHz)
Protocol	HTTP POST / JSON
Endpoint	`/JsonHandle` (port 80)
Request Types	`dashboard`, `cellStates`
Cycle	~250 ms (~4 Hz polling)
Configuration	SSID, password, and IP via web interface
Use Cases	Web dashboards, mobile apps, BattPulse Display 7″, remote monitoring

USB

Diagnostics and firmware updates

Parameter	Value
Connector	USB Type-C (or Micro-B depending on revision)
Interface	USB-to-UART bridge
Baud Rate	115200 8N1 (default)
Driver	CP210x (Windows driver may be required)
Use Cases	Serial diagnostics, firmware updates, debug console

CAN ID Summary

CAN ID(s)	Direction	Content	DLC	Cycle
`0x300`	BMS → Ext	Pack voltage, current, SOC, status	7	100 ms
`0x301`	BMS → Ext	Max/min cell voltage, temp extremes	8	100 ms
`0x302`	BMS → Ext	Energy, capacity, SOH (reserved)	—	—
`0x330`–`0x337`	BMS → Ext	Cell voltages (2 cells per frame)	4	100 ms
`0x350`–`0x351`	BMS → Ext	Temperature probes (4 per frame)	8	100 ms
`0x360`	BMS → Ext	I/O states (FETs, balancing, DI)	2	100 ms
`0x370`	BMS → Ext	Fault / warning bitmask	4	100 ms
`0x3A0`	Ext → BMS	Command frame (restart)	5	On demand

ℹ️ Full Protocol Details

For frame byte layouts, code examples, and WiFi JSON payloads, see the Developer API Reference.

6. Digital Inputs & Outputs

Digital Outputs (Contactor Control)

Output	Default Function	Type	Notes
DO1	Charge contactor	Low-side MOSFET switch	Connects relay GND side
DO2	Discharge contactor	Low-side MOSFET switch	Connects relay GND side
DO3	Auxiliary	Low-side MOSFET switch	General purpose

💡 Wiring Contactor Outputs

The digital outputs are negative-side (low-side) switching MOSFETs. Power your relay or contactor directly with the rated voltage; connect the GND side of the relay to DO1 or DO2. The BMS switches the ground path.

Digital Inputs (Galvanically Isolated)

Input	Voltage Range	Isolation	Connector Pin
DI1	24–70 V DC	Galvanic	DI1+ / DI1−
DI2	24–70 V DC	Galvanic	DI2+ / DI2−
AC Detect 1	AC 230 V	Galvanic	AC (pin 3)
AC Detect 2	AC 230 V	Galvanic	AC (pin 6)

⚠️ DI2 Pin Note

Current production boards may have DI2+ and DI2− reversed on the PCB silkscreen. If DI2 does not respond correctly, swap the + and − wires. The inputs are protected for pin reversal.

7. Connectors & Pinouts

Connector Placement

A) Sense & Balance — 43025-1800 (18-pin)

Pin	Signal	Pin	Signal
1	GND	10	GND
2	Bat1	11	Bat2
3	Bat3	12	Bat4
4	Bat5	13	Bat6
5	Bat7	14	Bat8
6	Bat9	15	Bat10
7	Bat11	16	Bat12
8	Bat13	17	Bat14
9	Bat15	18	Bat16

B) Contactor Output — 43025-0400 (4-pin)

Pin	Signal	Description
1	DO3	Digital Output 3 (auxiliary)
2	GND	Ground reference
3	DO1	Digital Output 1 (charge contactor)
4	DO2	Digital Output 2 (discharge contactor)

C) Shunt & CAN Communication — 43025-0600 (6-pin)

Pin	Signal	Description
1	3V3	3.3 V reference (shunt power)
2	SCL	I²C clock (shunt)
3	SDA	I²C data (shunt)
4	CAN-H	CAN Bus High
5	CAN-L	CAN Bus Low
6	GND	Ground reference (shunt)

D) Digital Input — 43025-0600 (6-pin)

Pin	Signal	Description
1	DI1+	Digital Input 1 positive (24–70 V)
2	DI1−	Digital Input 1 negative
3	AC	AC detect input 1
4	DI2+	Digital Input 2 positive (24–70 V)
5	DI2−	Digital Input 2 negative
6	AC	AC detect input 2

E) Temperature Sensor — 43025-1000 (10-pin)

Pin	Signal	Description
1	TMP1	NTC Probe 1
2	TMP2	NTC Probe 2
3	TMP3	NTC Probe 3
4	TMP4	NTC Probe 4
5	TMP5	NTC Probe 5
6	GND	Ground (shared)
7	GND	Ground (shared)
8	TMP8	NTC Probe 8
9	TMP7	NTC Probe 7
10	TMP6	NTC Probe 6

Connector Summary

Connector	Molex P/N (Housing)	Pins	Function
Sense & Balance	43025-1800	18	Cell voltage sense + passive balancing
Contactor Output	43025-0400	4	DO1, DO2, DO3 + GND
Shunt & CAN	43025-0600	6	Shunt I²C + CAN-H/CAN-L + GND
Digital Input	43025-0600	6	DI1, DI2, AC detect × 2
Temperature	43025-1000	10	8 NTC probes + 2 GND

8. Mechanical & Environmental

Parameter	Value
PCB Layers	Multi-layer
Mounting	4 × M3 mounting holes
Operating Temperature	−20 to +60 °C
Storage Temperature	−40 to +85 °C
Humidity	5–95% RH (non-condensing)
Conformal Coating	Optional (contact sales)

ℹ️ Dimensions

For exact board dimensions and mounting hole positions, refer to the mechanical drawing supplied with your order or contact info@battpulse.com.

9. Daisy-Chain & High-Voltage Packs

For battery packs exceeding 16S, the BattPulse Leader BMS supports a daisy-chain architecture with one master unit and up to 15 slave units.

Parameter	Value
Maximum Slave Units	15
Total Cell Count	Up to 126S (16S × ~8 units, configurable)
Communication (inter-board)	Isolated serial daisy-chain
Target Voltage Class	400 V / 800 V packs
Isolation	Galvanic isolation between stack levels

💡 Daisy-Chain Configuration

Each slave unit monitors its own 6–16S segment and reports cell data to the master via the daisy-chain bus. The master aggregates all data and exposes it on the CAN Bus and WiFi interfaces. Contact info@battpulse.com for daisy-chain wiring details and high-voltage pack design guidance.

10. Ecosystem & Compatibility

BattPulse Display 7″

The BattPulse Leader BMS is natively compatible with the BattPulse BMS Display 7″. Both CAN and WiFi work out of the box:

Connection	Setup	Data Rate
CAN Bus	Wire CAN-H/CAN-L. Match baud rate. Data appears automatically.	100 ms (10 Hz)
WiFi	Same network. Enter BMS IP. Select BattPulse type.	~250 ms (~4 Hz)

Third-Party Integration

The open Developer API (CAN + WiFi) allows integration with:

Custom LCD/TFT displays and HMIs
Vehicle ECUs and inverters (CAN interface)
Data loggers (CAN or WiFi)
SCADA and industrial monitoring systems
Custom mobile apps and web dashboards (WiFi/JSON)
Home automation and IoT platforms

ℹ️ Open API for Integrators

The BattPulse Developer API is open to integrators of all sizes. Full CAN frame layouts and WiFi JSON schemas are documented in the Developer API Reference.

🛒 Complete BMS + Display Solution

Pair the BattPulse Leader BMS with the BattPulse Display 7″ for a plug-and-play battery monitoring system.

🔋 Get the BMS → 🖥 Get the Display →

11. Ordering Information

Model	Description	Includes
BP-BMS-001	BattPulse Leader BMS (single master unit)	BMS board + 5 mate connector housings with crimp pins (18-pin, 4-pin, 6-pin × 2, 10-pin)

Accessories (Sold Separately)

Item	Description
NTC Probes	100K 3950 NTC temperature probes (pack of 4 or 8)
BP-DSP-7001	BattPulse BMS Display 7″ — touchscreen LCD monitor
Shunt Sensor	High-precision current shunt (rated for your application current)
Slave Units	Additional BMS boards for daisy-chain configurations (contact sales)

How to Order

Online: battpulse.com/product/battpulse-leader-battery-management-system
OEM / Volume: Contact info@battpulse.com for volume pricing and customisation options.
Partnership / Integration: We supply BMS systems to EV conversion shops, HV pack builders, and OEM integrators. Contact us for partnership details.

12. Document Revision History

Revision	Date	Changes
1.0	March 2026	Initial release