Many regions (like California and New York) now legally require new installations to be sealed 10-year battery units to prevent residents from "borrowing" batteries for TV remotes and leaving the home unprotected.… When the rhythmic, high-pitched “chirp” echoed through his hallway, the man knew the drill. He twisted the smoke detector off its bracket, expecting to swap out a standard 9V battery. Instead, he found a specialized CR17335 lithium cell with a proprietary snap-on connector. The Specialized Search He headed to Store A, a local hobbyist electronics shop. The clerk shook his head. “That’s a specialized 3V lithium pack. We carry the cells, but not with that specific wiring harness. Most manufacturers do that to prevent people from using underpowered off-the-shelf batteries. Try an online wholesaler.” Determined to fix it that day, he went to Store B, a large home improvement warehouse. The specialist there gav...