BattPulse

Contents

1. What’s in the Box
2. BMS Overview
3. Connectors & Pinouts
4. Wiring Steps
5. First Power-On
6. Connecting a Display or Logger
7. Safety Notes

1. What’s in the Box

2. BMS Overview

Key Specifications

Connector Placement

All connectors are located around the edges of the BMS board. Refer to the diagram below for placement:

3. Connectors & Pinouts

All connectors on the BattPulse Leader BMS use the Molex Micro-Fit 3.0 system — locking, automotive-grade connectors rated for high reliability and vibration resistance.

A) Sense & Balance Connector

Micro-Fit 3.0 — 43025-1800 (18-pin)

B) Contactor Output Connector

Micro-Fit 3.0 — 43025-0400 (4-pin)

C) Shunt & CAN Communication Connector

Micro-Fit 3.0 — 43025-0600 (6-pin)

D) Digital Input Connector

Micro-Fit 3.0 — 43025-0600 (6-pin)

E) Temperature Sensor Connector

Micro-Fit 3.0 — 43025-1000 (10-pin)

4. Wiring Steps

1 Prepare the Connectors

• Strip wire ends and crimp them into the supplied Micro-Fit 3.0 crimp pins using the appropriate crimping tool.
• Insert crimped wires into the mate connector housings according to the pinout tables above.
• Verify each pin — a click confirms the pin is locked in the housing.

2 Wire the Sense & Balance Connector

• Connect the cell balance leads from your battery pack to the Sense & Balance connector.
• Pin 1 (GND) connects to the pack negative terminal.
• Bat1 connects to the top of cell 1, Bat2 to the top of cell 2, and so on.
• For packs smaller than 16S, only wire the cells in use.

3 Wire the Shunt & CAN Connector

• Connect the current shunt sensor to pins 1–3 (3V3, SCL, SDA) and pin 6 (GND).
• Connect CAN-H (pin 4) and CAN-L (pin 5) to your CAN bus network or display.
• Turn the jumper to add a 120 Ω termination resistor at each end of the CAN bus if not already done.

4 Wire the Contactor Outputs (They are negative side switching mosfets)

• Connect DO1, DO2, DO3 to your contactors or relays as needed. your relay will be powered directly with the rated voltage and GND side of the relay will be connected to the DO1 or DO2
• Pin 2 (GND) is the ground reference for the outputs. (Optional)

5 Connect Temperature Probes (Optional)

• Connect each NTC probe between its TMP pin and one of the GND pins (pin 6 or 7).
• Use 100K 3950 NTC thermistors.
• Configure the probe count in BMS settings to match the number of connected probes.

5. First Power-On

Power-On Checklist

• All balance leads are correctly wired and seated
• Shunt sensor is connected (3V3, SCL, SDA, GND)
• CAN bus wiring is correct (CAN-H, CAN-L) with termination
• No short circuits between adjacent pins
• Battery pack is within safe voltage range

1 Apply Power

The BMS is powered from the battery pack through the Sense & Balance connector. Once the balance leads are connected to a charged pack, the BMS will power on automatically.

2 Verify Operation

• The on-board LEDs will indicate power and communication status.
• CAN bus frames begin transmitting immediately at 100 ms intervals (see Developer API Reference for frame details).
• If a BattPulse Display 7″ is connected via CAN, data will appear on the display automatically.

3 Configure BMS Settings

Access the BMS web interface to configure:

• Cell count (6S–16S)
• Number of NTC temperature probes
• Current sensor calibration
• Overvoltage / undervoltage / overtemperature thresholds
• Contactor output behaviour

6. Connecting a Display or Logger

CAN Bus Connection (Recommended)

The fastest and simplest way to view BMS data. The BattPulse Display 7″ is natively compatible:

1. Wire CAN-H and CAN-L from the BMS connector to your display or data logger.
2. Ensure 120 Ω termination at both ends of the bus.
3. Set baud rate to 500 kbps.
4. Data appears automatically — no configuration needed.

WiFi Connection

Connect your device (display, laptop, phone) to the same WiFi network as the BMS. Then write the BMS IP on the browser. It will start polling the data over http:

• Endpoint: http://<BMS_IP>/JsonHandle
• Method: POST with JSON body
• Request types: {"type":"dashboard"} or {"type":"cellStates"}

See the Developer API Reference for complete protocol details and code examples.

7. Common Questions & Troubleshooting

Q: I connected the USB cable but I can't see anything at 115200 baud — why?

Most USB problems are caused by the cable or drivers, not the BMS. Try these steps in order:

1. Try a different USB cable — some cables only provide power and do not carry data.
2. On Windows, install the CP210x USB-to-UART driver if your OS does not automatically recognise the device. On most Linux distributions no additional driver is required.
3. Confirm you are using the correct serial settings in your terminal program. The BMS console (if present) typically uses 115200 8N1; however, some tools/devices may use different rates — double-check the product notes.
4. Test with another PC or USB port to rule out host-side USB faults.

Q: CAN Bus doesn't work — what should I check?

Use the checklist below to find common CAN bus problems:

• Baud rate: Ensure both devices (BMS and display/logger) are set to the same baud rate. The BattPulse system uses 500 kbps by default.
• Termination resistors: A proper CAN bus requires a 120 Ω termination resistor at each physical end of the bus. Verify that both ends have 120 Ω in place.
• On-board termination switches: The BMS includes internal termination; some displays have a switch on the back to enable/disable termination. If the display is acting as one end of the bus, enable its 120 Ω switch. If both ends have termination enabled twice (two resistors at same end), you will get incorrect loading — make sure exactly one 120 Ω is present at each physical end.
• Wiring: Confirm CAN-H is connected to CAN-H and CAN-L to CAN-L on every device. Keep the CAN pair twisted and avoid long stubs.
• Bus length & topology: Use a linear bus topology; avoid star or long unterminated stubs.
• Ground reference: CAN is differential, but if an external device requires a ground reference connect chassis or ground appropriately (use shunt GND if needed).
• Transceiver power: Ensure both transceivers are powered (3.3 V or 5 V as required).
• Tools: Use a CAN adapter or analyser (e.g., Peak, Kvaser, or a USB-CAN dongle) to verify traffic and fault conditions.

Q: Where is a quick CAN checklist?

See the CAN Bus checklist above and the short link in the Shunt & CAN section for quick reference.

Q: OLED screen is flickering — what can I do?

Flicker is commonly caused by electrical noise or an unstable power source. Try these mitigations:

• Move the OLED and its cables away from noisy power supplies (AC/DC adapters, DC/DC converters, motor controllers).
• Use twisted-pair wiring and shielded cable for the display signals where possible; keep power and signal cables separated from noisy bundles.
• Add ferrite beads on the display power cable and ensure good grounding practice.
• Try powering the display from a separate, low-noise supply to see if the problem follows the supply.
• Check and secure all ground connections — poor grounds are a common source of flicker.

8. Safety Notes