The battery was trickier. Replacement cells were available, but the monitor’s casing left only a sliver of clearance; a larger cell would not fit. She had an old watch battery in the drawer — not ideal, but it seated snugly when she trimmed a millimeter from an insulating spacer. Kapton tape sealed the edges and protected the tiny circuit from the threatened moisture of the evening.
Elena found the cracked case in a half-empty drawer beneath a stack of instruction manuals and grocery lists — the tiny round monitor she’d bought two summers ago to keep tabs on her bike lights. Its plastic shell had a hairline fracture snaking from the charging port to the LED ring, and inside a small sliver of circuitry gleamed like an exposed tooth. The device still blinked faintly when she tapped it, but its Bluetooth icon never stayed solid for long. bluetooth battery monitor crack