Have'nt had any trouble with mine.......Yet!
The Varta part number is YTX 14-BS....it's also a Yuasa standard# (the standard Yuasa is not a sealed battery though, but does cross to a maintenance free version.
Most dealers that get their parts from aftermarket sources such as Parts Unlimited, Tucker Rocky Etc should be able to get you one easily.
Also, this number will cross to many options if you buy over the internet:
If you want a sealed battery in about 3-4 days you could try Dennis Kirk and search for part# 20-0848 (Drag Specialties: High Performance type)$71.95
For a high power AGM (absorbed glass mat) type search for part#20-0375 (Power Max GTX 14-BS High Power AGM type) $71.99...these are supposedly more durable than gel. Both are sealed maintenance-free.
Battery Specialists in Greenville,SC (1-800-BATTERY) should be able to get you any battery that fits.
Battery Mart has an AGM "Big Crank" ETX 14 equivelant. See links below.
A battery for a 99-02 Triumph Speed Triple/Daytona, 91-02 Honda ST1100, or 97-98 Yamaha YZF1000R is the same #...among others
http://www.denniskirk.com
http://www.abatterystore.com
http://www.batterymart.com
Hope that helps you some!
Lorin