My bike is 2010 model. I'm not sure if later models do not suffer from this problem but I recommend to get voltmeter installed on your bike. It is small investment you can get one on ebay for few pounds. That is what I did. You can just connect it to battery, you don't need to play with any existing wiring. It allows you to keep an eye on any charging issues and sometimes even warn you before problem become serious-my case.