Your Critter runs on one replaceable 18650 lithium-ion cell. Use the right cell, charge it inside the light, and store it sensibly, and it will look after you for years.
The right battery
The Critter is built around one exact cell. A different size or type can stop it working, or damage the electronics for good.
- Format
- 18650 lithium-ion
- Size
- 18.4 mm x 65 mmabout 0.72" x 2.56"
- Positive end
- Flat topno raised button
- Protection
- Unprotectedprotected cells are longer
- Voltage
- 3.6 V nominal4.2 V fully charged
- Capacity
- 2500 mAh or moreours is 2500 mAh; higher runs longer
- Run time
- Up to 7 hoursabout 2 hours on full white
- Discharge
- High-drainrated 30 A continuous
Official replacement cell
The same cell that ships in every Critter BT, ready to swap in seconds.
Shop the battery, $9.95Watch how to charge
US addresses only. Shipping rules stop us sending spare cells abroad or by overnight service. Outside the US, buy one locally to the spec in this table.
Buying a cell locally
Get any of these wrong and the cell may not fit, or may damage the light. Check them before you buy.
Look for
- 18650, flat top, unprotected, 3.6 or 3.7 V
- A high-drain cell from a well-known maker. Any real capacity works, and a higher one just runs longer.
- A specialist battery shop, not an anonymous marketplace seller
- An intact wrap with no dents, tears or bare metal
Avoid
- Protected cells, a few mm longer than the Critter is built for
- Button-top cells, also too long
- 3.2 V LiFePO4 or 1.5 V lithium cells, the wrong voltage
- "Fire" style brands claiming 6000 to 9900 mAh, which no real 18650 delivers
Everyday care
Charge
- Inside the Critter, over USB-C, with the included cable
- From a plain USB-A adapter, 1.5 A or more. Fast-charge (USB-PD) bricks may not power it.
- Pulsing red means charging. Blinking red means a bad USB source.
- At room temperature, somewhere you can see it
Store
- Hold Power for 1 second to sleep. A quick tap is standby and keeps draining.
- Away for 2 to 3 weeks or more? Take the cell out and leave it about half charged.
- Cool and dry, never in a hot car
Travel
- Spare cells go in carry-on only, never checked bags
- Cover the ends: a case, tape, or one cell per bag
- Never loose with keys or coins
- About 9 Wh, far under the 100 Wh airline limit
Retire it
- Any dent, torn wrap or bare metal
- Ran unusually hot while charging or in use
- Drains on its own, or run time has collapsed
- Recycle it at a battery drop-off, never household trash
If a cell gets hot, hisses or swells
- Stop using it and unplug the charger right away.
- Move it outside or onto a non-flammable surface, away from anything that can burn.
- If it catches fire, douse it with plenty of water. Don't try to hold it.
- Never charge or use that cell again.
Keep learning
Lithium-ion cells can catch fire or burst if they are damaged, mishandled or used outside the manufacturer's ratings. Please read and follow the guidance above. Ants on a Melon is not responsible for injury or damage caused by misuse or mishandling of rechargeable batteries, or by cells other than the one supplied with your Critter.
