I won't bother with new glass, i tried that on a couple of others and it was not successful long term, anyway, they don't seem to be bothered by the rain.
It will get them eventually. The voltage on the cells will cause galvanic corrosion of the power takeoff electrodes.
You won't see that in a couple days - but it will eat your cells, probably within months.
Galvanic croorosion = electroplating, and will eat up the sacrificial electrode - or one side of a piece of metal in the path - in extremely short order. (It's always a surprise to boaters how fast their underwater metal fittings turn to sponge when they moor in an "electrically dirty" dock, such as one with some boats whose shorepower feeds' grounds are hooked to the boats' 12v system, throwing DC into the water. If the victim boaters don't change their zinks on a short schedule, or if they have metal through-hulls that aren't zinc protected, they've got sponge brass within weeks weeks.)
You probably don't have to glue them to a plate of glass. But you DO have to keep 'em dry.