Forgive me if it is already in the above, but....
With any such system: Build in some hysterisis
By which I mean:
Fix it so that IF the generator comes on at all, then it will run for at least, say, 10 minutes.
Such things (internal combustion engine powered devices generally, especially those started by an electric motor served by a lead acid battery) do not take kindly to "short cycling", e.g. being started once every ten minutes, but only being allowed to run for 20 seconds each time.
While obviously, you wouldn't PLAN on your system invoking short cycling, do all that you can to design it so that even when something isn't working as expected, short cycling scenarios are not likely.
Discrete modules which say "if I come on at all, I will stay on for at least..." are available... talk to your local HVAC contractor.