Well, splash guards will have the pockets to collect water. I have RallyArmor flaps on my truck. They're flat and flexible. Sounds like they are exactly what you are looking for. :)
Did you try resetting the battery sensor?
https://www.fordservicecontent.com/Ford_Content/vdirsnet/OwnerManual/Home/Content?variantid=8914&languageCode=en&countryCode=USA&Uid=G2246222&ProcUid=G2243071&userMarket=USA&div=f&vFilteringEnabled=False&buildtype=web