It is not a nice situation but back in April 2011. I went to press the starter button and nothing happened. The first thought is that the electrics have failed but in this case it was the charger. I have a trickle charger connected all the time and the halfords charger gave up. It stopped charging and the battery was low as the alarm drains voltage from the bike.
Changing the charger and connecting up the battery within a few hours a press of the starter and the bike fired up….
If you have a bike outside in the elements then keeping the bike on a trickle charger has to help. Do you maintain your battery in any other way