Rechargeable lamps: run time, batteries and what the numbers mean

Rechargeable night lights are more useful than plugged-in ones because they go where you are. The specifications, however, are quoted in a way that flatters them, and it is worth knowing how to read them.

Run time is a best case

A lamp advertised at fifteen hours is almost certainly quoting the lowest brightness with no colour cycling. At a usable brightness, expect a fraction of that. A lamp at half brightness typically runs somewhere between a third and a half of the quoted figure.

That is not dishonest, it is just the convention. Read the number as a comparison between lamps rather than a promise.

Capacity is the comparable number

Battery capacity in milliamp-hours lets you compare two lamps regardless of how each brand measures run time. A 1800mAh lamp will genuinely outlast a 600mAh one of similar output.

Where a listing gives capacity, we print it. Where the manufacturer does not publish it, we say so rather than estimating.

Charging port

USB-C is worth insisting on. Micro-USB lamps still exist and they mean keeping a second cable in the house purely for the lamp, which is exactly the cable that will be missing at the wrong moment.

Check whether the lamp can be used while charging; not all can, and the ones that cannot are frustrating.

Battery care

Lithium cells do not like being stored fully flat or being left at 100% for months. If a lamp is being put away for a season, charge it to roughly half and top it up occasionally.

Repeated full discharges shorten the life of the cell more than anything else you can do.

Silicone and touch controls

Soft silicone lamps are pleasant to hold and easy to clean, and they are the format most often used for baby night lights because they are soft and light. Touch controls are convenient but wake up easily in a bag — check whether there is a lock.

A lamp that switches itself on in a changing bag will be flat when you need it.

Memory function

A lamp that remembers its last brightness and colour saves you scrolling through settings in the dark. It is a small feature that makes a large difference to whether the lamp actually gets used.

Where a lamp has it, our listing says so.

Timers and auto-off

A 30 or 60 minute timer is useful for going to sleep and unhelpful for a night feed, where continuous low light is what you want. Look for a lamp with both, or one that lets you disable the timer.

Check whether the timer resets when the lamp is switched off; some do not.

What to compare

Capacity in mAh, charging port, whether it runs while charging, whether it remembers its setting, and whether the timer can be turned off. Those five decide how a rechargeable lamp lives with you. All are on our listings where the manufacturer publishes them.

Charging routine

The lamps that stay useful are the ones with a charging habit attached. Putting the lamp on charge at the same point each day — when the room is tidied, or when the monitor goes on — means it is never flat when it matters.

Where a lamp charges by USB-C, keeping a dedicated short cable plugged in near where the lamp lives removes the last excuse. A cable that has to be found is a cable that will not be used.

Signs a battery is failing

Lithium cells lose capacity gradually and then quite suddenly. The warning signs are a run time that has halved, a lamp that gets noticeably warm on charge, or any swelling of a silicone body. The last of those means stop using it immediately.

Most small night lights have sealed batteries that cannot be replaced, so a failing cell is the end of the lamp. Dispose of it at a battery recycling point rather than in household waste — lithium cells in a bin lorry are a genuine fire risk.

Charging safely overnight

Charge on a hard surface rather than on a bed or under a cushion, and use the cable and adapter the lamp came with or a good-quality equivalent. Most problems with small rechargeable devices come from a cheap adapter rather than from the device.

A lamp that is warm while charging is normal; one that is hot is not, and should be unplugged and retired. None of this is unique to night lights, but a nursery is the room where it is worth being careful about.

The short version

• Quoted run time is at minimum brightness, almost always.
• Battery capacity in mAh lets you compare across brands.
• USB-C charging is worth insisting on now.
• Lithium batteries prefer to be stored part-charged, not flat.

From our shelves

• Egg Light for Nursery, Baby Night Light for Feedings & Diaper Changes — $18.99
• Baby Night Light, 0 Blue-Light Nursery Egg Light for Breastfeeding, Flip Design, Soft BPA Free — $24.17
• Egg Light for Nursery, Rechargeable Touch-Control Baby Night Light — $24.99

Where to go next

Browse the full range on the shop page, read the frequently asked questions before ordering, or check delivery timing on the Shipping Policy page. If you would rather ask a person, contact us — the phone reaches the counter.