Installed a small solar panel system on a narrowboat to keep the batteries topped-up through the summer when not cruising.
Panel mounted on roof
Cable inlet box to right of picture is sealed to roof and has waterproof gland inlet
Electrics cupboard – Charge controller on RH wall
Close up of Dual Battery Solar Controller
Cable from solar panels running through calorifier cupboard, through new hole in floor to battery compartment
Battery compartment – Black charging cables appearing from top of picture positives connected through fuse holders (small red wire)
New Batteries & Upgraded Cables
Charger Installed
nb wrens-nest 
Good to see you’re not letting your mobile electrics skills get rusty.