CR2032 lithium coin cell batteries power devices like car key fobs, Air Tags, Samsung's Smart Tag2, and smart home sensors. Before blaming gadgets for sudden failures, check the battery first. Inspect visually for crusty residue, rust-colored patches, swelling, or leakage—if present, replace immediately.
Test with a multimeter: set it to DC voltage (20V range), touch red probe to positive face and black to negative center. A fresh CR2032 reads near 3V, while 2.5V indicates replacement time. However, multimeters draw minimal current, so a good reading doesn't guarantee performance under load.
Alternative methods include a dedicated coin-cell tester (~$10) or LED test: red/yellow LEDs need less voltage and will light if the battery can supply current. For Air Tags, check Find My app for 'Low Battery' warnings before testing. Apple recommends batteries labeled 'Compatible with Apple Air Tag', with both brands claiming over a year of life.
Always store removed batteries safely and recycle properly.
Source: Engadget · Summarized by HeadlinesBriefing