The light on my other half's bike is sticking on (showing current charge level) and is completely unresponsive. In fact it came on of it's own accord the other day, until it turned itself off. It has stuck on during a ride and then cleared after a full charge. It is now sticking on again. The bike has had heavy wet weather / winter use and I can't help thinking there may be water in the button or elsewhere. It occasionally has error code 36 showing which is a lights error, but it has no lights. Anyone else encountered this or similar? How much is a replacement button? Bike is only done 1000 miles but is now out of warranty.