I ran a Di2 battery in a Conti saddle pack with a hole poked in it for a year or so until @chak gifted me a proper battery mount from the Evans spare parts bin.
I don't want to be taking up valuable storage space. I reckon it might fit below the post. I need to get the length of the battery to find out for sure.
I ran a Di2 battery in a Conti saddle pack with a hole poked in it for a year or so until @chak gifted me a proper battery mount from the Evans spare parts bin.