You do not need to connect directly to the battery.
You can use one of the positive posts under the seat, and a strong negative earth point elsewhere.
According to the picture I found below, you can use the permanent hook-up lead (top left) and then plug the charger into that as needed.
For a temporary hook-up, use the alligator clips connected in the same way.
Please read through this thread for detailed charging information: Battery Charging/Tender Thread

 

Thanks Captain,
That is helpful advice. I can manage to perform the connection without involving a BMW technician and the resulting cost.

 

How much cost this solar panel? I need more solar panels for my house. That is why I looking for more information. Also I found this review websolarguide.com/am-best-flexible-solar-panels/

 

In the UK it costs £100 for the panel and another £15 for an extension cable which most people will need.

 

When setting up your Optimate Solar Panel Trickle Charger, the direct connection to the battery terminals is indeed the recommended approach. It ensures the charger can efficiently deliver power to your battery without any potential voltage drop or interference that could occur if connected elsewhere in the electrical system.

 

For many vehicles, including motorcycles like yours, accessing the battery terminals under the tank is usually straightforward enough for connecting such accessories.