Hi there, I think you are creating a rod for your own back here, there is more to this then stepping up the voltage to 230v and changing from DC to AC to run power tools, I would look into getting a battery powered joiners power tool kit with spare batteries to boot.
The moment you start upping voltages of batteries you have a dilemma of safety , earthing arrangments etc, also 230v power tools with motors will generate inrushes of up to 10 times full load currents and you need to carefully consider whether the batteries can handle this, the moment you start pushing past 50v you are starting to get into voltage levels that are dangerous and any equipment + batteries you would require to do this would be far heavier than a generator set.
This is why Generators are still used on site with no power still as its the most practical method even if its just charging up your batteries on your power tools.