The appliance is not waterproof and is not suitable for use in the shower. The product data does not contain any information on waterproofness and the mode of operation described relates exclusively to window cleaning.
It depends more on the degree of soiling of the windows; the device itself only helps to remove the water/soapy water. With the microfibre cloth on the spray bottle, however, it is certainly possible to get by without soap (or with a water/spray mixture) if the soiling is moderate...
The device is a rechargeable battery device that works independently of the mains and is recharged using the charger supplied. As far as I know, all WV5 window cleaners are equipped in this way.
For 81.90 there is the Kärcher WV 5 Premium in yellow, with a bottle of concentrate and comes with the new spray bottle.
For 79.90 you can get the Kärcher WV 5 Premium in white and the old spray bottle.
Kärcher spare parts can be ordered directly from the manufacturer (see spare parts list for the WV 5 Premium: https://s4.kaercher-media.com/documents...).
Here are the contact details:
Kärcher AG
Industriestrasse 16
CH-8108 Dällikon
Tel: 0844 850 863
Fax: 0844 850 865
E-mail: info@ch.kaercher.com