My YUASA died on me this morning (I shouted "you failed me!!!" as per the Vincent Gray character in The Sixth Sense). It's probably a couple of years old. I've been through about 3 or 4 similar in the 7 years I've owned the bike.
My SS had a branded / copy Yuasa (lead acid conventional top-up type) when I got it. It didn't get changed for about seven years and as far as I could tell from receipts from the previous owner it was already two years old when I got the bike. I only topped it up twice and charged it twice in those seven years.
My bad. Nothing wrong with battery, which is in fact a Varta. Looks like I had a dodgy connection between the solenoid and the battery. There was nothing at the starter button, not even a twitch. I played with the leads and power was restored. Glorious.
So to throw in my two penny worth, I have Hawker Oddesy batteries fitted to both my bikes, but it doesn't matter what battery you have if the starter cables are not up to the job, see @Exige for some cracking replacements
Before season I put in a new Yuasa AGM battery in my SSie and installed a new set of OEM champion spark plugs. Seem to work good. Have read that using other than OEM spark plugs can give various issues, so I stick with the Champions.
