Micra 2004 & Flat battery?

[cylinder150]

Does anyone have info about why a micra 2004 will flatten its battery if not used for a couple of weeks. Garage says it is a common fault but they can't offer any explanation. (PS It's not the boot light staying or coming on - slept in boot overnight in total darkness to prove it!)

Also, as I service the car myself, can the 'Maintenance Reminder' message be switched off without a trip to the garage?

 

[Belle427]

any car battery is likely to lose its charge after a couple of weeks,try to use the car a bit more

 

[bob-the-builder]