So I will try and repalce with 2W/0,1 Ohm resistor first and see what happens.
I've already swapped FET, and checked power diodes - seems ok for now.
I have a set of new ones in case something is wrong.
If there is built in charger - I don't know. There are some power diodes, but there is also an external charger.
Hello! I've contacted Kowalski service in Germany and they told me, that the resistor is 0,18R 2,5W ). After replacing nothing happened - the light didn't work. After spending some time looking on circuit board I've found one broken track !!!! I've repaired it and now everything works!! Thanks for all suggestions!!