This video assumes the use of a stock Onewheel XR battery enclosure and stock harness. 3D printed enclosures are not recommended, as they likely do not have the flex required to properly fit the battery. While the video covers modifying the stock harness to fit, I would personally recommend either making your own or purchasing one from MakersPEV. This will be much easier to work with and avoid having to sacrifice your stock harness, which can be saved for a different build or sold aftermarket for a fairly good value.
Either route you go, make sure the polarity between the harness and battery match! The CBCSO uses standard polarity, as does the MakersPEV custom harness. If using the stock harness (uses REVERSE polarity), follow the installation video on how to modify accordingly. Modification is necessary, an adapter to switch polarity will likely not work due to the tight fit.
Huh, interesting. I hadn’t tried until I built the board but it wouldn’t connect until I plugged the board in to charge, like described. It also usually requires me to turn on the board to wake up the BMS and connect.