Just wondering, I had 90% charge this morning and with heavy use battery was flat within four to five hours :/ And with medium use I get around 12 hours, do I have a bad arse battery...I mean, I have a spare and with medium to heavy use this hour I've used 10% of the battery already, Is this normal?

My wife achieves similar. She's usually lucky to get a full waking day with a full charge.