Foam and electrical tape. I took a lot of force for me to remove this from my COBL GOBLR post the other day. I had another setup that used metal plate bolted to a split suspension seatpost but that became detached from the battery. The battery has sat in the Mason seattube for most of last year's races without issue.
EDIT: Dunno why this popped up again as unread. But have answer #2..
Foam and electrical tape. I took a lot of force for me to remove this from my COBL GOBLR post the other day. I had another setup that used metal plate bolted to a split suspension seatpost but that became detached from the battery. The battery has sat in the Mason seattube for most of last year's races without issue.
EDIT: Dunno why this popped up again as unread. But have answer #2..