2009 XC70 - remote key battery draining

[LC23]

Hi all - I have a 2009 XC70 with the comfort access option. I have lost count of the number of times I have had to replace the batteries in both remote fobs (it is anywhere between 1 to 3 months) and wondered if anyone can shed light on this issue? I have changed the actual car battery for a new Varta so have ruled that out. The other thing I can think of is there may be an issue with the central remote locking module in the car? The remotes dont seem to have much range either and you need to be right by the car for the buttons to work.

[LC23]

I've got the six button remote so by the sounds of things this should work a little better than it does....