leisure battery replacement under waranty

just had my broadway for 18 months and the leisure battery is showing every sign of failure has any one had success at claiming on warranty,  book is a little vague

Hi
   The battery should have its own guarentee,I would check that first,but your dealer should help you depending how far away he is
  regards Alan

Interesting... I have had problems with my battery on the Bourton.. It's in for a number of warranty issues in a few weeks.. Battery problems are number 1.  

A. It does not hold a charge
B. On mains charge it only ever gets to 78%
C. Drops from 78% to 50% in a day with nothing on.
Van is 4 months old

When our battery gave up whilst still within its own warranty date, I initially paid for the replacement with the original being sent to the manufacturer to check if it was due to a fault.  Refund was made shortly after when it proved there was a fault.