I seem to have killed a Motobatt MBTX9U in just under two years.
The battery was installed on February 27, 2012. I had a minor getoff in October of 2013, and after patching things up I rode off and on (well, mostly off, due to work) through November. December 2013 I didn't get any riding in, between major projects, overtime and a two week vacation. I put the bike on a tender in December, just to be on the safe side. Well, last week I needed to take the bike to work and found a very dead battery that wouldn't even turn the ST1300 over.
I pulled the Motobatt and placed it on my big charger, set to a 2amp slow charge. It immediately showed a 75% charge, and after a couple of hours indicated 100% charge. I tested and saw 12.4v at the battery terminals, but as soon as I put any load on the battery the voltage dropped to the mid 8's. The battery came back up to 12v, but then dropped to mid 8s again under load, without starting the bike. That's pretty much dead in my book.
The date code stamped onto the top of my battery shows "150711", and I'm guessing that's the 15th of July, 2011. This would put the age of the battery at failure to be right around 2.5yrs old. I'm not expecting any replacement through warranty, but I am a bit disappointed that I didn't get the life I was expecting from it. Of course, I only paid about $70 dollars, so I'm trying to convince myself that $35 a year isn't a terrible cost of ownership. Why does it seem so hard to find a battery at a reasonable price that lasts longer than 3 or 4 years?