Low Battery Light vs Fault Light

Low battery and fault lights can look similar

Many devices use red, orange, yellow, or blinking lights for both low battery and fault conditions. That can make it hard to know whether the fix is simple or serious.

Signs it may be low battery

• The device still works but chirps, blinks, or warns occasionally.
• The light appears after months of normal use.
• The device uses replaceable batteries or a rechargeable pack.
• The app or display shows low battery.
• The light changes after charging or replacing batteries.

Signs it may be a fault

• The light returns immediately after a fresh battery.
• The device will not start, connect, charge, or complete setup.
• The light appears with heat, smell, swelling, smoke, or physical damage.
• The light is an alternating diagnostic code.
• The official manual calls the pattern a fault, service, or end-of-life signal.

Safety note

For smoke alarms, carbon monoxide detectors, medical devices, chargers, batteries, and vehicle warnings, do not assume a light is only low battery unless the official manual confirms it.

Related next steps

After using this guide, try the Find a Light tool, browse by device type, or check the safety-critical lights hub if the warning may involve risk.