If you cannot place the BT-DN110 Internal Battery in your bike's frame you have two options: either use the BM-DN100 external battery mount and the SM-BTR1 battery, or use the SM-BTC1 external mount for the internal battery. In most cases using the SM-BTC1 is the better option. It has several advantages:
- You can use it with both SM-BTR2 (previous internal battery) and the newer BT-DN110 battery
- It uses a low profile design and attaches to a frame's bottle cage mounts
- You can use SM-BCR2 to charge the bike instead of SM-BCR1
It features 6 t-Tube ports with a cable organizer - it functions as a Junction B.