Tboyster

I have plugged in a small compressor to this outlet and it didn’t have enough power to run the pump. Pump just made a weird noise and I unplugged it. I am now getting a sluggish start when it cranks over and a couple times now the battery acts as if it’s dead and won’t start the truck, needs jumped. I have had the battery tested (it’s a high output gel battery) and it still tests fine. Could it be a relay that is bad draining the battery when it’s parked? And if so where would it be located? I would think the inverter has to have a relay or module somewhere.