lekutei sichos vol 27- bechukosai 3 - Rabbi Nechemia Deitsch

I know you love to give charity.The question is are you allowed to give charity more than 10%? Is there a cap at all on the amount of charity you want to give away.The Rambam says that if somebody gives away more than 20% of their earnings to charity is considered to be a fool.How does this reconcile in other places where he says that if there is a great need, you’re allowed to give away without limitation. ?