1 year ago I bought a new Braille 11 lbs dry mat nano tech splinter cell twin screwed bla bla bla battery as mentioned in this post: http://www.mazdaspeedy.com/2008/04/new-battery.html

This is supposed to be the king of all automotive batteries.  Yet it is FUBAR after 1 year.
I parked my car in late september 2008, disconnected the battery 14 days later when removing the ECU. 
When I was to start the car 5 months later it was empty.  I was not that surprised and connected the charger and waited some hours while I was doing some other stuff.
The car barely started.  The next day the battery was dead.
Charged the battery 8 hours.  Battery dead the next day.
Charged the battery 26 hours.  Batter completly dead.  It could not even power the light in the boot/trunk.
No point in returning it due to shipping charges.  They'll probably tell me I broke the warranty since I did not trickle/pulse/power/ - charge it with their certified big $ charger every 15 minutes during the 5 months it was disconnected.

My turd Golf 1 lead acid stone age battery lasted over 5 years with hard cold winters and nothing resembling care and maintenance.

I have now ordered a WestCo MX-5 battery from MX5parts.co.uk since every one says they are the best.  Hopefully this will last longer than the Braille crap.