It seems that everyone is afraid to tell you that your 4 hr problem lies in your "converter" The Wfco 8900 series is a slow charger. I will stop short of calling it a junk converter,....... 99% of them don't work like they were supposed to be designed to work. Anyone that is a serious dry camper, trash cans their Wfco !
Short, and in reality, all you need is a true 3-4 stage converter charger, like the PD 9200 series, even in a 45 amp will probably change your 4 hrs to 2 hrs.
Or you could go solar,......if you don't have to spend most your time praying for sun, or a big tree doesn't get in the way.
I have solar, and very impressed w/ it,......but only while the sun is shining.