They're not housed inside the frame with nowhere for water to go though. Last few times I've taken my seatpost out it's been pretty damp in there, and noticed this morning a little corrosion on the battery terminal bit. Anyway, all seems fine now, sealed up the hole and wrapped the connections in some inner tube to see if that stops it happening again
Be cautious about wrapping electronics. Letting water out is more important than stopping it from getting in, since you will always fail at the latter.
They're not housed inside the frame with nowhere for water to go though. Last few times I've taken my seatpost out it's been pretty damp in there, and noticed this morning a little corrosion on the battery terminal bit. Anyway, all seems fine now, sealed up the hole and wrapped the connections in some inner tube to see if that stops it happening again