New guy building electric wagon

I have an old mobility scooter that I am using the elictronics from to try and build a powered wagon to haul stuff to and from Ballgames. My question is the scooter was powered by two ub12350 batteries in Parallel I would like to use one battery and only need enough power to run for an hour tops at walking speed. Can that be done? Also the batteries are dead fron non use for three years how and I check to see if they are useable or should I just buy new one(s)?

Most are connected series. If it is indeed connected parallel, using one is fine.