Long life battery separator

A process for making a battery separator comprising:

• contacting a nonwoven noncellulosic substrate web with a solution of cellulose having at least 95% .alpha.-cellulose in a solvent of N-methyl-morpholine-n-oxide while forming said substrate into a tube;
• converting said solution to a solid cellulose having a degree of polymerization of at least 350 by removing said solvent to form a cellulose coated tubular substrate;
• washing and drying said tubular coated substrate to provide a glycerine-free battery separator having a coated substrate thickness of 10 mils or less;
• wherein penetration of said cellulose coating into said nonwoven substrate is controlled to provide a delamination resistant battery separator having an absorption rate of at least 6 mm/5 min of an aqueous 30 wt. % KOH solution and a 30% KOH absorption capacity of at least 200 g/m.sup.2 and a retained wet tensile strength of at least 70% after 41 days in an aqueous solution of 40% KOH.