Gilera 125 ST battery problems

[MrLarner]

Hi guys,
I bought a Gilera 125 ST last week, and everything was fine, been parked in my garage for the last 5 days, on day 3 i went into the garage and noticed my dashboard was lit up, which i found really strange as the keys was in my hand,
4th day and same thing, but light went out after a few mins, then today i went in to turn the bike on, and the battery was 100% flat.
anyone have experience with what has happened?
does the dashboard light up to inform me that my battery is running low? when i say dashboard, i mean the lights where the speedo/time/petrol is.
the actual bike lights at front and back was not on.
I just find it strange that the dashboard was lit up considering no keys was in the bike.
any idea's or help would be really appreciated.
thanks guys.