The solar cells are definitely replaceable. Panasonic, among others, manufactures them, and any Casio-authorized dealer should be able to source OEM-grade solar

The solar cells are definitely replaceable. Panasonic, among others, manufactures them, and any Casio-authorized dealer should be able to source OEM-grade solar cells for you. It is by all appearances a standard coin-style battery, but rechargeable. My experience is that cost of ownership of solar models is much lower versus battery models, with less hassle (esp. if atomic syncing is an option). I just had the solar cell in an 18-year-old 5600 replaced. Not because it urgently needed it, but because it was clear the endurance without charging was declining a bit, and I was at the shop, anyway. (And I was pushing it on the seals.) An OEM spec cell is ~$15-25 with retail markup, but my guy charged me about that for the swap, including new seals and a pressure test. OEM resins are still available for that model, too. I'm still running the original resin, but on other watches when replacing it I always bank a spare for the next swap. Not that the battery models are bad, and they are definitely more field-serviceable given the comparative difficulty of finding suitable solar cells in more remote parts of the world. There's really no bad G-Shock, just what works better for one's preferences and requirements.