It's not water getting into the battery that's the problem. It's water/dirt getting to the bearings of the motor and corroding them.Granted I have the old style removable e8010 battery, but if I’m going to apply water to bike I always remove the battery ,wash , dry,wait overnight and keep bike in a warm place to totally dry out on the fear that water will short circuit something. I have zero proof that this is a good idea but it seems right to me