First things first, if the batteries have corroded, dispose of them according to your local waste authority guidelines, or ...
Paint sprayer nozzles get clogged if you don't flush them with cleaning fluid so it's definitely worth spending time on ...
Cleaning your panels once or twice a year can keep them in top shape. Always turn off your panels before cleaning them. Know where your solar array's DC shut-off is, and know/learn the procedure for ...
I'll confess: my MacBook's keyboard has seen better days. I've been meaning to clean it for a while, but I always put it off because of how hard Apple makes disabling the keyboard in general: Whenever ...