Yep, have had a lot to do with batteries over the years and your symptoms sound right, 5 years is a good run out of an automotive battery.
The part number on the battery is important as the last couple of letters usually tells you the orientation of the pos and neg terminals, quite easy to connect em arse about if you get the wrong one. Look for a mark on the battery (though you might need a magnifying glass) stamped on the terminal, marked on the side of the case or it may have a red plastic doovy around the positive terminal and a blue one around the neg. The YUASA are marked clearly on the side of the case.
More info.
http://www.gsyuasabatteries.com.au/a...pe=56&type=608
