Hobot 198 Mode D'emploi page 52

Power adapter/DC extension cable
How to clean the glass
Step I: "Dry Clean" first
Use a clean and dry cleaning cloth to clean dust and dirt from the glass.
 If there is water or detergent on the cloth or glass, the water or detergent will mix together with
the dust or dirt to become mud, making cleaning results bad.

Using HOBOT on sunny days or days with low humidity for best results.

Don't use HOBOT on rainy or high humidity days, otherwise it will produce white streaks.
The white streaks are water molecules. This is the same thing that can happen when
manually cleaning with a cloth.
Step II: Use a clean and dry cleaning cloth. Keep the cleaning cloth on the upper wheel clean and dry.
Spray a little detergent (1~2 sprays) on the lower wheel's cleaning cloth, but not too much (if
too wet, the machine can't move well), then clean the glass again.