First, this question should be posted in the
Electrical section of the Forum. The Mods may move it for you.
The link 2000 is the
control panel. It is connected to the actual battery charger, probably a Freedom 10 or 20. You need to locate that: it is the size of large shoebox in a heavy metal case with a
cooling fan. Make sure it has adequate
cooling.
The Link 2000 does two things: it will
monitor the status of your house battery bank, and a second battery if there is one: voltage, amps in or out, amp-hours consumed. The second thing is that it controls the function of the Freedom battery charger.
When you
plug into
shore power, the battery charger will detect AC and begin
charging your batteries according to a 3 phase algorithm; Bulk, Acceptance, and Float. It also has an
equalization stage that can be manually selected. If you are not on AC, it will convert 12V from the battery to 110 volts if you select the
inverter function.
I have attached the manual for the Freedom charger. It has a lot of good basic information in it. You don't need to be an electrical
engineer, but you do need to learn and understand basic
boat electrical systems.
I also suggest you get a good book, like Boatowners Mechanical and Electrical Manual by Nigel Calder.