^Like a typical 10A charger wont draw near as much as your converter which is probably 30-50A?
Many ways to skin the cat here to keep your power usage in check.
But another “bonus” you get from many “bargain” generators as you termed it, is they don’t put out the power or duty cycle of a quality generator. NRA mentioned that as well.
Consider that. Being cheap sometimes isn’t the most economical in the long run.
IMO, spend $500-600 on a nice used Honda or Yami 2k if a new one isn’t in the budget and it’ll virtually run forever and if you sell it 10 years from now, it’ll still be worth good $.