Your slides should operate w/o a battery, if your unit is plugged in and the converter is operating to provide the 12v power.
That said, frequently converters alone (or batteries alone) do not supply enough power to operate high draw items like slides and levelers, which can cause fuses to blow.
It is always recommended to have fully charged batteries and another power source (generator, shore power, tow vehicle) to assist in the power demand of slides.
So definitely check and charge your battery(s). Also check your converter output, breakers and fuses,
Scott and Liz - Southern NM
2012 Wildcat Sterling 32RL - w/level up (best option ever)
2007 Chevy 2500HD 4dr short bed Duramax w/allison
Reese Fifth Airborne air ride king pin coupler with Sidewinder