Some can, some can not, Depends on your converter and selected other systems in the RV.
For example.. Many older RVs have a Magnetek 6300 converter, this unit needs a battery to work properly.
Some RV's have special Energy Management Systems.. Now that term applies to two different devices..ONE uses only mains power (120vac) to power itself,,the other however can use 12 VDC to run its computer.. And this one is the one that decides if things like the air conditioners and water heater work when you are on 30 amps. (Load shedding).
A handy device many RVers should carry is a Jump-Start pack,, This is a small AGM battery in a carying case with jumper cables attached. Useful if your car is not interesting in starting it can also Sub for the missing battery in the RV when needed... I prefer the ones WITHOUT the built in extra stuff (Radio, Air Compressor, Inverters, Lights,though lights are optional) but if you want one that WILL start your car go for ones with MORE than750 peak amps.
NOTE The battery is only in the 20 amp hour range (Roughly 1/10 of a pair of GC-2) so it will not run your RV long.. But it will make the Magnetek happy.