Oh for 90 bucks Horrible Freight (Might even be cheaper) has a nice small 450 Amp Lithium battery
Click here to see it And for 75 NAPA has a 1,000 amp lead acid (heavy) one
Again click here Fully charge the battery
Go to the generator. the actual generator Find the RED lug with the 12 volt line hook the RED cable to it.
Hook the Black cable to any handy Generator FRAME part
Start the Generator
Leave the battery hooked up for at least 1 minute or till you hear the Transfer switch or the Generator load down as the Transfer switch engages.
Make sure the Generator breaker does not trip.. then unhook the battery
Wait a while
Try to start it
Oh you will likely need a new Chassis battery.. House batteries depends GC-2 MIGHT recover.. MARINE/deep cycle will need replacement.