mcgivor ✭✭✭✭✭✭

The ceiling fan idea is impossible as described, the source must always be greater than the than the end output, there will be losses in every step so from the 100W panel you may, if it were possible…

Measure the loads before jumping to conclusions , just because the shore power connection is rated at 30A maximum, it not nessersary what one would use. When using batteries to power anything, conser…

The best method would be to use a motor rated relay with the foot pedal controlling the relay coil current only, this would prevent the foot pedal wiring from becoming a fuse. 

The current needed to keep the presets is probably miniscule, leaving the radio connected directly to the bank would probably have no significant drain, over a short period of time.

Buy new, that way the history is known, there are so many things that could have happened with used, why take the risk? New Golf cart batteries are worth far more than a second hand set of unknown 2 …