Pack assembly

Here are step-by-step instructions to build the battery pack from individual cells, install the Battery Management System (BMS), and complete the assembly securely.

0. Preparing the Cells

• Check Voltage:

  • Use a multimeter to ensure all battery cells have the same voltage (precision to 0.01V is not necessary; around 3.55V is acceptable). Ensure all cells are at equal voltage before assembly.

  • This step is crucial for battery health and safety.

1. Inserting Cells into the Spacer

• Identify Polarity:

  • The spacer is marked with plus (+) and minus (–) signs. Always match cell polarity to the spacer markings.

  • Insert each cell so that its negative end matches the minus sign on the spacer.

• Group Arrangement:

  • Double check the arrangement on these pictures:

2. Installing the BMS (Battery Management System)

• Handle Carefully:

  • Avoid touching the BMS electronics directly to prevent electrostatic damage.

• Connect BMS:

  • Plug the BMS into the connectors on the cell assembly; the connectors are keyed to prevent incorrect installation.

 

3. Closing and compressing the pack

• Place Top Spacer:

  • Position the top part of the pack and press it gently into place.

• Insert Screws:

  • Insert four screws into the side holes using the provided Allen keys.

  • Tighten screws so there is less than 1mm gap between the two spacers.

  • Do not force the screws; if resistance is felt, check alignment and thread lock.

LED should be blinking orange. It means the battery need to be setup. That will be done later, once the antenna is plugged.

Casing Assembly

The video demonstrates how to assemble the casing for a Gouach battery pack, covering all steps from preparing the casing components to inserting the battery pack and making all necessary connections.

1. Installing the handle

2. Installing the connector block

• The cover has all required cables for the bike’s communication and power.

• Place the 2 seals.

• Insert all cables into the casing, ensuring none are pinched.

• Secure the cover with four small screws (do not overtighten).

• Arrange the cables neatly in the provided cavities to prevent obstruction when inserting the battery pack.

3. Preparing for Battery Pack Insertion

• Set aside the top part and the LED plastic cover for later.

• Insert the battery pack with the BMS facing down, aligning it with centering features inside the casing.

4. Connecting Internal Cables

• Main Connector: Plug in the white connector gently until a click is felt.
  

• Antenna Connection: Attach the antenna plug to the ESP32 module; ensure it clicks into place and route the cable between the reboot button and ESP32.
  

• Tuck cables into the center and gently lower the pack until it sits at the bottom.
• Power Connectors: Plug the red with red and black with  cables. Careful to place them so that they are at the same height as the BMS.

5. Configure your battery using the App or the Desktop app

For this step you can use either:

• Android app 
• Iphone app
• Use Chrome on your computer

 Once you connect, a prompt will ask you to chose:

• your cell model (if yours is not present you can ask us: contact@gouach.com). 
• your motor brand or model 
• the configuration (normally you have only one choice at present)

Then you need to press the button behind the LED (Clear Error Button) and press "Save" on the app. The battery should reboot.

If the LED are green, you can close the pack. If the LEDs are purple, you will need to clear the errors that occurred during the assembly:

• Clear Errors:

  • If all four led are purple, it indicates a “permanent failure” (often normal during assembly as the BMS detects unusual conditions).

  • Press the small switch on top of the BMS to clear the error for 4 seconds 
  • Once you do this, you should see 1 to 4 led in green depending on the charge of the battery. 

  •  

6. Closing the Casing

• Place the top cover, starting with the bottom and aligning centering pins.

• Ensure the seal remains correctly positioned and unpinched.

• Secure the casing with two long screws at the front and additional screws on the sides (do not overtighten).

• As you tighten the screws, the casing compresses the seal, ensuring waterproofing.

• Once assembled, check that everything is neat and the LED is visible.

• Avoid excessive torque to prevent thread damage.

Done !

We remind you that lithium-ion cells can be dangerous and should be handled with care. At the moment, we have no support for LFP (LiFePo) cells and they should not be used. Only use NMC cells whose nominal voltage is 3,6V. You'll find example of suitable cells on the cell supplier page. We recommend to wear protective equipment and to have bucket of water to drown the battery in case your cells get out of control.

We provide a printable A3 version in PDF here if you prefer.