"Frequent deep cycling wears them out quicker.

Best charge level for storage is 40%.
10% self discharge on day 1.
Higher temperature reduces life expectancy drastically (up to 30-40%!!!!)
The battery heats up during the later stage of the charging cycle and during discharging.
Hot batteries do not accept charging well.
A deep discharge (to about 80% DoD) is recommended each three months.

The way I have been charging the Vectux so far was wrong:
The battery temperature of my Vectux has been over 30°C just about every time it was charged. I have usually charged it right after driving it home, after hard uphill work, with a warm to hot battery each time, often around 40°C. At the end of charging the battery would usually still be around 30°C warm. This will increase the self-discharge rate.

Ideally, the scooter should be driven until the battery is around 1/2 empty or fuller, then left standing to let the batteries cool down, then charge when the batteries are about 20°C and just before using the scooter again.
A timer should be used to delay the onset of charging, rather then to turn the charger off.
This should have a significant impact on life expectancy of the battery, at least in warm to hot climates and during summer in moderate climates.

One big problem in hot weather is that the batteries are packed away so securely that they do not cool down readily without forced air cooling. They remain warm to hot for days, therefore aging more rapidly then necessary.

I have therefore re-wired the battery housing cooling fans, so that I can turn them off or run them independently of the Vectux electronic by connecting an external 12V DC source. Each of the two fans draws 2.2A @ 12V. This will allow me to cool the batteries down before charging, so they will accept a full charge quickly and live longer. Range should improve that way because more energy gets accepted by the battery during charging, and less will be lost to self discharge."