Ninebot Max and Ryobi 40V batteries to extend range

[upisloud]

Complete newbie to hacking...

I have a Ninebot Max (purchased new Aug 2022) I have several Ryobi 40V lawnmower batteries I have been using on my ebikes with great success! I would like to use them as range extenders for the scooter but Im nervous about bricking it or other bad things.

I don't want speed enhancements or any other performance improvements, I just want to use the Ryobi battery, on it's own, not in series or parallel with the stock battery. What is the simplest and safest way to do this?