Thanks "Haylands", new battery fitted a few weeks ago, not long bought the car, seems might have been going on a while as it had one last year as well according to service history!!

Headlamp wipers work and park, sat nav is switching off, it does have the Nokia Hf kit still in it, are these fused separately, ie how can I disconnect it??

Bit of an update.. Decided to find cause and cure battery going flat before I spend the money on the transfer box motor, just in case they are linked, re low voltage etc.. removed fuses from in car phone and sat nav/stereo amp etc. Waited 5 days as battery is always flat then if car not used, it started!!! Happy days, and has done so every day since... But, heater blower not working, switches light up, just no blower, im presuming this is a coincidence as its a different fuse circuit, I had bought an FSR anyway, just to eliminate it, but have not fitted it yet. I have now replaced the sat nav etc fuse, and am leaving it a few days to see if battery goes flat, then at least I know which circuits are causing the problem!!
Thanks again to all for your help everyone..