In short, it doesn't work.
I drove through a giant puddle caused by ex-hurricane Fay. Eri has been really worried about that; she seems to think it'll destroy my car or something. (In reality, the water isn't conductive enough to cause a problem in the motor. In fact, it would help cool it. The dirt in the water is problematic, but not a huge deal.) My engine compartment is organized so that nothing important got wet.
But it got in my spare tire well, which is where my charger resides. It apparently got wet, because turning it on tripped my GFCI.
I let it dry out for a day or so. I planned to use a hair dryer on its fan ports if it wasn't dry, but yesterday morning I started charging as usual. Today I'm all full.