My Samsung S25 was at 4% when I connected it to my usual Samsung fast charger. The percentage increased much faster than normal, and after roughly five minutes the phone reported a full 100% charge. It also stayed at 100% while I was using it instead of dropping to 99%. The battery has otherwise been behaving normally, aside from the usual gradual decline in battery life. I restarted the phone, and afterward it displayed a more realistic percentage again. Could this have been a software or battery-monitoring glitch, or should I be concerned about the battery itself?
3 Answers
This was probably a temporary error in the battery percentage display rather than the phone actually charging from 4% to 100% in a few minutes. Restarting forced the system to read the battery information again, which explains why the percentage returned to normal.
Phones do not directly measure the exact amount of charge left. A fuel-gauge chip estimates it using voltage, current, temperature, and the battery’s expected capacity. Those estimates can drift or occasionally become confused, causing the displayed percentage to jump. The charging safeguards should still prevent overcharging, overheating, or unsafe discharge.
It may have been a bad reading from the battery gauge or another software hiccup. If it happens again, install any available system update and restart the phone. Occasional recalibration can help, but repeatedly draining a lithium-ion battery completely is unnecessary and can add wear. If the problem becomes frequent, the battery drains unusually fast, or the phone gets hot or swells, have it inspected.
That seems to be what happened. The reading went back to normal after restarting, so hopefully it was just a one-time glitch.