I have been given a 12volt Supercold machine that came out of a boat but didn't come with a cold plate. I want to install the type that can make ice cubes. my question is of how to charge the system once it is all installed and connected. I have not ordered the manual yet but since I am a complete novice at refrigeration, can you give me the short version on how it should go together and what to avoid. Thank you very much for any info you can share.Regards,Dave