Protective cases, carrying cases, casings, covers, and waterproof cases and covers specially adapted for mobile electronic devices, namely, cell phones, smartphones, portable media players, electronic tablets, electronic book readers, and laptop computers; holsters and folios specially adapted for holding or carrying mobile electronic devices, namely, for cell phones, smartphones, portable media players, electronic tablets, electronic book readers, and laptop computers; headphones, component parts for headphones, namely, ear cups, earphones, headphone adaptors, and ear buds; display screen protectors for providing protection, shade, and privacy specially adapted to mobile electronic devices, namely, cell phones, smartphones, portable media players, electronic tablets, electronic book readers, and laptop computers; battery management systems consisting of rechargeable batteries and operating firmware in cases that house and electrically connect to mobile electronic devices; battery management systems consisting of batteries, firmware, and computer hardware for use in managing, monitoring, and extending battery lives of mobile electronic devices, namely, cell phones, smartphones, portable media players, electronic tablets, electronic book readers, and laptop computers all housed in protective cases that connect to electronic devices; universal battery packs that electronically connect to electronic devices, namely, cell phones, smartphones, portable media players, electronic tablets, electronic book readers, and laptop computers