Fungineers BMS User Guide

Thank you for purchasing the Fungineers BMS. I promise you that this BMS will add reliability and peace of mind to your Funwheel/ DIY Onewheel. Let's begin!


1. General Information and warnings:

It is very important that you read the information on this page thoroughly or watch the associated videos in order to understand your new BMS. Don't worry, its simple and intuitive. 

Please note that Lithium batteries are dangerous, and proceed at your own risk. This is not a toy and is not recommended for ages less than 14 years. 


2. Understanding your BMS:

The Fungineers BMS is compatible with 12S to 20S Lithium Ion Battery packs. 

To use the BMS out of the box, a 20S lithium battery is required. If you have an 18S Battery pack, please wire the battery pack as per the below: 

As you can see, one pair of connectors is shorted on the upper 10 cells and lower 10 cells, please make sure you know what you are doing, and only short the connectors on the BMS and NOT THE CELLS!

Ok, now that you have your battery, let's see how you can connect and run the BMS. 


3. Contents:

What is Included:

With your purchase of the BMS, you will receive the BMS, BMS connectors, Bluetooth Module and Bluetooth module to BMS connector.

What is included

The BMS: The BMS consists of 2 PCBs connected via header pins and screws to save space.

BMS Module

The BMS has an XT30 female connector for the charge port and a male XT30 connector for connecting to the battery (on some later revisions the XT30 connectors are placed in between 2 modules for improved safety).

There are 2 sets of JST connectors to connect to individual cells, and there is a 4 pin connector to connect to the bluetooth/ CAN module that is provided with the BMS. There are also 2 temperature probes that can be placed in the battery enclosure or between the battery cells themselves. Let's talk a bit more about connectors.



4. Connecting the BMS for the first time:

First step is to connect the Battery connector and charge connector as shown.

The XT30 connectors are marked as shown in the picture below. The B+ and B- connector is where the XT30 female from the battery should connect, and the C+ and C- is where the Charger XT30 male should go to. 

XT30 connectors


 Assuming your battery is already wired up with the correct JST PH2.0mm connectors (10 pin for the upper, higher voltage cells, and 11 pin for cells 11 to 20, and B-), lets connect the to the BMS.


Step 2 is to connect the lower 10 cells as shown:

Lower 10 cells


Step 3 is to connect the higher voltage 10 cells (Cells 11 to 20, and B-):

High voltage 10 cells


Now the Bluetooth module can be connected, and the BMS should be ready to be connected to your phone. 

Download the Bluetooth app from here:



Enable Bluetooth and location on your phone, and open the app.

Tap the Bluetooth icon, and search for your module's name (in case module is not discoverable, connect the charger and restart the app).

Tap on the Bluetooth module name, and you should see the main page of the app populate with individual cell voltages and charge status. 


Enjoy your BMS!

5. Operation philosophy:

The BMS is a charge-only BMS, which means the discharge is bypassed for safety reasons. For simplicity, the BMS doesnt have any on/off switch. It switches on whenever a charger is connected, and stays ON until the cell voltages go below 4.1V. The bluetooth can be connected to your phone anytime during or after charging until the cells hit 4.1V. 
The BMS also has a self-turn-off feature to save battery and ensure safety. 

The BMS has been designed meticulously along with our partner company who specializes in BMS and Safety devices, to ensure you are safe and confident in your DIY Funwheel build. 

6. Size and fitment:

The BMS measure 135x35mm with a max height of 15mm. It can fit most enclosures, but it is designed specifically to fit the Funwheel Battery enclosure along with upto a 20S2P 18650 battery. 


 7. Final words:

We thank you for your support. If you have any further questions, please join us on Discord and post them on the Discord BMS and Battery channel. 

See you there. 



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