I have had a Braun electric toothbrush which is rechargeable from mains for about 2-3 years and obviously use it at least twice a day. Over the last few months it has been running out of power faster and faster, to the point where I had to keep it permanently on the recharger. Now it is not recharging at all. Do I have to get a whole new toothbrush and charger set? Can I just get a new rechargeable battery? Sorry to ask pathetic question but terribly busy and can't face big trip at weekend to electrical shop carrying toothbrush and charger all day long in handbag.