My Dad's after a good charger/conditioner for his 4x4 Sapphire Cosworth that can be left on for a week or two at a time between startups and over the winter period.

I like the look of the C-Tek XS range but where do you stop?... the 3600 looks a good piece of kit for the money, the 4003 is a little bit more, the 7000 a bit more on top of that and so on...

...will the 3600 be good enough or is it worth paying more for what he wants?