So I bring in a G-shock with a solar battery and asked for a regular battery. The jeweler has lithium batteries in stock, but told me I would have to go elsewhere for my solar batteries. I have been replacing the solar batteries with lithiums for years, but I do get jewelers who think doing this might cause the battery to explode or be damaged. Remember the solar cell is still charging the battery.
I don't have any citation for this one way or another. If what I do causes no harm, I should have something more than "personal experience". I will also contact Casio, but I'd like some feedback in this forum.
Gene -- The Casio Fiend