Battery should not run down when plugged in. The WFCO is either dying or dead. WFCO should hold 13.6 volts on the battery at all times. I would replace with a different brand. Go with IOTA, Progressive Dynamics or Powermaster. 30 to 35 amps is fine unless you go with more than two batteries.
www.bestconverter.com2000w inverter is huge power from a battery. You really need 400+ amp hours to run this size inverter in a practical manner.
I power my tv, dvd, laptop and charge small items with a Go Power 300w sine wave inverter.
I mounted the inverter behind the fuse-breaker panel. 12v connects to the main battery feed to the panel. 120v is wired into the entertainment area circuit with an automatic transfer switch. The wiring is very straight forward if you have done any home wiring before. The Go Power 300w has a provision for a remote power switch so with the touch of a button I have instant power.
GP 300w SW $172Xantrex 15 amp switch $49So all in maybe $250-$300 for self install.
