do the math
the inverter beeps at the low battery alarm 11v ? the instructions & specs tell you what the low voltage set point alarm is
LED lights .. very little power
sat receiver 25w aka 2amps at 12v ..TV power needs ? how big is the TV, is there a home theater sound system .. where is the power going ?
2.5 hrs !! you should be good for at least 6 hrs of TV maybe even 10hrs
i'm sorry you don't like our opinions
but unless you can show some huge power use
you have to face the facts, the batteries are not supplying what they should be capable of
to give you an 'Analogy' your batteries are like a milk jug full of rocks
you can pour in water but it takes less to reach the full line, maybe 1/2 gallon
so when you pour it back out (aka use power) you can only get 1/2 volume
you are the only one who thinks they are good