led light bulb with battery backup

Rechargeable screw‑in bulbs charge when left on—manufacturer instructions often recommend keeping the bulb on for about 10 consecutive hours to fully charge. In a power outage the bulb switches to battery backup automatically, and many designs let you unscrew the bulb to use it as a handheld flashlight.

Stick‑on portable bulbs typically have an integrated, non‑removable base, while rechargeable backup A19/A21 bulbs commonly use the standard Edison medium screw base (E26).

Stick‑on bulbs generally use a slide‑off base so you can replace batteries without removing the mounted unit; listings show replaceable AAA batteries (models use either 3 AAA or 4 AAA depending on the product).

They're commonly used for general and utility lighting in closets, pantries, cabinets, basements, garages, sheds, and for outdoor or camping use and emergency power‑outage preparedness.

Some models add features such as a 90° adjustable angle, shatterproof construction, built‑in motion sensors with standby mode, magnetic mounting, or a collapsible hanging loop.