How should Nissan respond to dropping capacity?

[TonyWilliams]

Can you confirm that there was no fan found anywhere inside the battery casing and that the whole outer casing is sealed? The slide deck at http://www.nhtsa.gov/pdf/ev/Nissan_Presentation-Bob_Yakushi.pptx" onclick="window.open(this.href);return false; mentions it's sealed and shows a 1 hour immersion test.

The service manual also confirms all this for the past two years. No surprises here.