Ninebot ESX Error Code 44
"External battery has default S/N, change external battery"
If your Ninebot ESX(ES1, ES2, ES3, or ES4) or SNSC (1.0 or 1.1) is beeping or has a red wrench icon and flashes this code, read below.
If you clicked the wrong error code, go back to the Error Code Index.
This error is caused by the BMS having the default serial number of 4KA0017A1A0001.
This can happen for any number of reasons but usually happens when flashing a firmware file with the serial number included.
To fix it, change the serial number to a different one by following the guide at Ninebot ESX Change BMS Serial Number.