Flat battery

[E.L.M.O]

My partner and I are now engaged

I proposed to her at a classic mini show (the same show I met her at 3 years previous)

Today we woke up a little late (it always happens on the days your running late, right?) and we were in a rush because we were due to go visit another possible wedding venue. the place is called Maiden Barns http://www.maidensbarn.com/ (if anyone has been there, please feel free to let us know whats its like as we never made our appointment today!) We were going to go in one of the minis but by the time we got the 8 out of the way (as it was blocking the minis) and then sorted the never ending 8s Alarm it was to late.

anyway, Ran out to the 8 as we were late and the car wouldnt unlock, so I ran in to get another key as I presumed the battery in the key had gone. Second key, nothing. So I manually opened the door and it didnt take long to realize that it was actually the 8s battery that had gone flat.

The thing is, it hasnt been used as much as it used to be, but its still had some fairly long runs recently. The battery is now on charge but I dont understand how it could have gone flat. Do you think it could have been fault?

Thans