I removed the back panel of my Galaxy S21 FE about a month ago and noticed a strong chemical odor coming from the battery. I opened it again today, and the smell may be even stronger. It seems somewhat sweet and causes a headache if I breathe it in for too long. The battery life has also become poor, lasting only around six hours on a full charge. I plan to replace the phone in a few months, but I'm worried the battery could be damaged or become dangerous. Should I keep using it, or is a replacement necessary?
1 Answer
A faint adhesive smell is possible after removing the back, but a strong sweet chemical odor—especially one that irritates you—should be treated as a damaged or leaking lithium battery. Stop using and charging the phone, move it away from flammable materials, and avoid opening, puncturing, squeezing, or testing the battery further. Have a qualified repair shop inspect it, or take it to an approved battery/electronics recycling facility. Don’t keep using it just because you plan to replace the phone soon; damaged batteries can swell, vent, ignite, or rupture without much warning.

The poor battery life makes the battery concern more serious. If the phone is warm, swollen, hissing, smoking, or producing a stronger odor, leave the area and contact local emergency or hazardous-waste services rather than transporting it yourself.