what will run 2 cf40 weaco per day

mate what turps are you drinking?
whatever it is mate this post is unintelligible and makes no damn sense

Just remember that in a lot of cases the DC output from a portable generator is generally low current output. You may gain a higher and charge rate and get better efficency vs time worth out of your running generator if you plug in a stand alone battery charger to the AC side of you genny.

Your gonna want about 100-150 amps of charge a day depending on temperature and how many times the fridges are opened.

If you only run the generator once a day then you'd want 200-300Ah of battery depending on type (if you take wet cells below 50% they tend to die in 6-12 months).

Also just coz you have a 50amp charger doesn't mean that the battery will accept 50 amps of charge - again depends on battery type.

Charging batteries above 80% take lots of time, not lots of amps.