I don’t think it matters too much. It’s designed to allow any water to drain away.
Just as well. Went for a cycle today, lots of puddles about. About 4 miles in before i noticed id forgot to put the battery compartment cover on. Battery got a good soaking.
Would like if there was an attachment point on the cover and a bit on the bike so it is attached loosely with a short cord etc,so you can remove it, but it not be totally seperate from the bike.
Cycled without it today, and have left it on my van bonnet before when finished, then drove off. Wondered what it was that blew up over the windscreen, and then remembered. Gotta make a checklist now when setting off and packing up !