It is worth noting as VicW says that the battery condition indicator is only fitted to one cell, any of the other 5 cells could have a problem and it would not show (shorted plates, low electrolyte etc. and condition indicator doesn't always show up sulphated cells) . I never leave a a battery on a car more than 5 years, even the high quality 'silver' and calcium' plate batteries are not guaranteed more than 5 years.
Batteries are not an expensive item and work hard without maintenance, Halfords batteries are pretty good and they normally have them on special - I just replaced my Civic battery with a Yuasa 'silver' battery for £70 on special at Halfords - proper bargain.
You need two cars or spare 12V battery - I bought a couple of fused cigarette lighter plugs from local car shop (about £2.99 each) and a 20M reel of cheap speaker cable about £10 (2 core with a white line on one core) - just connect marked core up to centre pin on plug ( + ) and unmarked core to outer of plug ( -), plug it into both cars and turn ignition key to 'aux' and you can happily disconnect bad battery and replace it without losing settings on radio etc.