The best rechargeable emergency light bulbs

A battery-backup bulb looks and screws in like any other bulb. Inside it there is a small lithium cell and a charging circuit. While the house has power, the bulb runs from the mains and keeps that cell topped up. When the power fails, it switches over and keeps lighting the room.

The rule that catches people out is simple: the bulb has to be switched on when the outage starts. It is not a sensor that notices darkness; it is a bulb that notices its own power has gone. A lamp switched off at the wall stays off.

That cuts both ways, and the second half is useful: flipping the wall switch off is how you turn the bulb off during an outage, so it does not burn its battery lighting an empty room at 3am. Switch it back on when you need it again.

The same rule decides where these belong. The battery only charges while the fixture is powered - GE says ten consecutive hours for a full initial charge - so a bulb in a lamp you use for five minutes a week is a bulb that will be flat when you need it.

This category has a documentation problem. Most of it is sold by brands that publish a battery capacity, an hour count and nothing else - no lumens, no CRI, no indication of what brightness that hour count assumes. The criteria below are mostly about separating what is specified from what is claimed.

1. A published runtime at a published brightness. "Up to 5 hours at 650 lumens" is a specification. "48 hours" with no level attached is a number on a box.
2. Lumens on mains, too. This is a bulb you live with every day and use in an emergency a few times a decade. If it is dim or green the rest of the time, the trade is a bad one.
3. Color temperature you can live with. The budget half of this category is daylight-only, which is fine in a hallway and wrong beside a bed.
4. Charging behavior, stated. How long it takes, and whether it charges only when switched on. GE publishes this; nobody else here does.
5. A warranty. A battery is a wear item. A 3-year warranty on a bulb with a cell in it says more than any runtime claim.

We did not test these bulbs, and we did not run a stopwatch on anyone's battery. Every figure here is the manufacturer's published specification, or the retailer listing where the maker publishes none, with the page it came from in the sources below.

GE LED+ Battery Backup A21 - the pick. 760 lumens on the mains, CRI 80, and GE publishes the part that matters: up to 5 hours at 650 lumens on a full charge, which takes 10 consecutive hours of being powered. It also unscrews and flips into a handheld flashlight, which is the feature you remember the first time you need to look under a sink in the dark.
Cons: GE's published page covers the soft white version, and the three selectable color temperatures on this listing are not on it; not dimmable; it charges only while the fixture is switched on; and in an outage it lights only if the switch was already on.

GE LED+ Battery Backup BR30 - for recessed cans. The same platform in the flood shape a can takes: 650 lumens, 2700K, CRI 80, up to 5 hours of backup, and GE states the backup comes on automatically when the power is out. A kitchen with three of these in the ceiling is a kitchen that still works in a storm.
Cons: 650 lm is modest for a can, so a ceiling of them is dimmer than ordinary BR30s; not dimmable, which rules it out of most living-room ceilings; indoor use only; and it is the most expensive way per bulb to add backup light.

BoRccdit KeepLit A19, 6-pack - the whole-house option. Six bulbs at a fraction of the price per socket, with three brightness levels in battery mode - which is the honest way to stretch runtime, and the reason the headline hour count is so much larger than GE's.
Cons: no lumen figure and no CRI published at all; the 48-hour claim is the listing's, at an unstated brightness, with no standard behind it; daylight only; and no manufacturer page we could open.

DEBAOBULB, 4-pack - the cheapest that works. 9 watts, 6000K, a published 1200mAh cell, four to a pack. If the goal is simply that some light exists in the hallway when the power goes, this is the least money that achieves it.
Cons: no lumens, no CRI, no runtime figure - a battery capacity on its own tells you nothing about how long it will run; 6000K is the coldest light here; and again, no manufacturer page.

One good bulb in the room you sit in. The GE A21. It is a bulb you can live with at 2700K and CRI 80 the rest of the time, which is the real test.

A kitchen or hallway of recessed cans. The GE BR30, in one or two of the cans rather than all of them - the ones over the counter you would want lit.

A house in a storm belt, on a budget. The BoRccdit six-pack, spread across the rooms you use at night, with the understanding that the published data is thin.

A rental you will leave in a year. Any of them - a bulb is the most portable lighting upgrade there is. The renter's set is in renter-friendly light fixtures.

Light that does not depend on a socket at all. That is a different product: a cordless table lamp or a rechargeable sconce, both of which run on their own battery all the time rather than only in an outage.

Put them where the switch gets used. It is the only way they stay charged, and it is the only way they are on when the power cuts.

Test one deliberately. Turn the lamp on, then kill the breaker for that circuit. You learn how bright it really is in backup and whether the battery took a charge - and you would rather learn that in daylight than during a storm.

Keep them off dimmers. None of these is dimmable. The failure mode is buzzing, flicker and a short life - dimmer compatibility covers why.

Do not expect them to replace a torch. Only the GE bulbs unscrew into a handheld light. The rest are fixed in the socket, which is fine for lighting a room and useless for looking in a cupboard.

Mind the color. Most of this category is 6000K daylight, which is stark in a bedroom and fine in a hallway. If it is going in a living space, the 2700K options are worth the difference - the case is in 2700K vs 3000K.