Ok, everyone handles things differently. I have 3 Gen1 vehicles and in my case the rear battery is continuously discharged at about 10 mA. A charged (healthy) battery comes so without charging after 20 to 25 days to the dangerous border with the deep-discharge. If now is not charged the voltage drops below the point where the Segway charger starts the charging process. In order now to be able to charge at all, the voltage has to be raised from the battery ! This can be done with the so called regeneration (reviver) equipment - or a simple 60V power supply ...
If I do not use the Segway long time I take off the rear battery.
And I never let the Segway constantly at the wall outlet.
For some people, it is useful to use a timer between wall outlet and Segway.
But I also have an advantage, I have used in my batteries a watt meter as you can see in the photo below. So I can at any time check the voltage of my battery :
Expertenakku - Prototyp mit Wattmeter - Kleineres Download.jpg