KARCHER WD 2-18 V-12/18 Battery + Kit Li-Ion / 1.628-500.01

Quick overview from the supplier:

Karcher WD 2-18 V-12/18 Battery + Kit 1.628-500.01 Li-Ion / 225 W / 12 l / 18 V / 2,5-5 Ah / 10-20 min