T18NC insane battery drain

Have had a pair of T18NC since June and they were pretty darn good for the first few months until about a month or so ago the battery drain has been getting progressively worse and worse. Nowadays I have to throw them back into the case for a charge anywhere between 5-7 times a day to get a work days worth of use out of them. At this point they might as well be un-useable.

Any suggestions?