Hi, I can put my TomTom Touch on charge all night and it will show as full in the morning, unplug it, put it back on and check the battery and it's on 2 or 3 bars. Charge it fully sometimes and then remove it from the charge and check the battery straight away and it's already lost one bar. It never lasts a full day now. Any ideas? Does it need a new battery - if that's even possible?!?