I often see watches for sale with ten year batteries fitted and indeed my brother has one. However the batteries i buy usually last no longer than three to six months, and cost around £5 fitted, Any one know the best battery and where i can get one? Preferebly a ten year one.
Three to six months doesn't seem very long. Mine usually last one to two years. I get them fitted at The Watch Lab or Samuels or somewhere like that, which ever is most convenient at the time.
You'll probably find it's down to the quality of the watches - the better the quality, the less current needed to run it and so the longer the battery lasts. There are batteries like the LR44 that come in two types - alkaline and silver - yet they're both labelled as LR44. You have to look carefully at the packaging, or at the battery itself, to see which is which. In this case the silver one lasts longer. But I'd guess it's your watch that's the problem. Why not think about a Citizen Eco-Drive? Solar powered - never needs a battery!
Ten-year batteries are invariably Lithium-type. They are quite thin but have a much larger diameter than silver oxide types so the two are not interchangeable. The watches are designed to take one type or the other as the voltages are also different. If, like me, you dislike the hassle and expense of frequent battery changes, I can also recommend light-powered watches (such as Citizen's Eco-drive range) - they can be quite inexpensive, are terrific quality and go on forever.