thanks guys for your tips! You provided me with useful information.
Yeah, the battery is weak. I am afraid I will not do without its replacement. I will try to drop to my mechanic, maybe he will help with the test.
The LED shopping is more complicated than I thought…
I also want to install it by myself not to hire the electrician.
Well, in the kitchenette I would like to install a tray fixture with three 12 Watt LED heads. It has 2661 lumens.
For outdoor lighting I found this lamp https://www.mrosupply.com/lighting/lighting-fixtures/sensor-light-fixtures/1431490_stl360_rab-lighting/
Surely, it will be in use only during stops in rv parks with hookups. Otherwise it will drain my battery.