Originally Posted by
blazin
True. Though I discovered one downside. I once had the Di2 battery in my seat post shaken loose during a long ride over some particularly rough gravel. Without tools, I was unable to fish the wire out from the seat tube to reconnect the battery and so had to single speed home. I suppose an eTap battery could get rattled loose too, but I carry a spare and can easily replace it.
insert the battery with the connector facing downwards, so even if the battery got loose it would still stay connected inside the seattube