need new batteries again??

My '03 F350 7.3 4x4 has is about 195,000. I replaced the batteries 07/2013. Shop is telling me they need replaced again. It's been colder this year (some negative temps), but nothing more than what the truck has seen in it's lifetime with me. Last set of batteries lasted 5 yrs with similar driving conditions.

Question: thoughts on what else could be wrong causing the battery drain?

Sent the truck in because of a chunky sounding hard start. Starter replaced 12/13/2013.

Thanks!