Li-ion & Charger: 18650 and 21700 Rechargeable Batteries
· Available today18650. 21700.
The cylindrical cells that high-drain devices were designed for.
3.34–3.6 V · Protected BMS · 500+ cycles
Shop the Series
3 cells. 1 charger. Pick by what you're powering.
Li-ion cells with protected button-top construction, discharge ratings of 6–21 A depending on the cell (21 A continuous on the 3,500 mAh Cold-Weather 18650), and capacities up to 18,000 mWh. Built for flashlights, headlamps, vapes, bike lights, and anything else that drains a cell harder than alkalines can survive.
The Companion Charger
One charger. Every cell in this series.
Model CW401
Bench Dock — 4-Bay 18650/21700 Battery Charger
LCD display, 4 independent bays, Li-ion cells only. Works with every cell in this series, including the 3.34 V Cold-Weather 18650, and with other common 3.6 V Li-ion cylindrical cells.
Why SCIGOLD Cylindrical
What every cell in this series shares.
True Li-ion chemistry. 3.6 V on the 18650 Standard and the 21700: about 4.2 V when full, about 2.5–3.0 V when empty. 3.34 V on the Cold-Weather 18650: 4.25 V charge cut-off, 2.3 V discharge cut-off.
Every cell carries its own rating: 6–7.5 A on the 18650 Standard (by capacity), 21 A continuous (3,500 mAh) or 12 A (4,000 mAh) on the Cold-Weather 18650, 12–15 A on the 21700. Enough for high-output flashlights, headlamps, and vape mods.
On-cell protection circuit for over-charge, over-discharge, short-circuit, and over-current.
Every cell is rated for 500 or more charge cycles. Over that life, one rechargeable cell stands in for hundreds of disposables.
Built For
The devices alkalines die in.
18650 and 21700 are the cells inside everything from your Tesla pack to your tactical flashlight. Here's where SCIGOLD's lineup lives in the consumer world.
01 · Tactical & Outdoor Lighting
Cut Through The Dark.
Many premium flashlights run on a protected 18650, from brands such as Fenix and Nitecore. Check the light's manual for the cell it needs.
The Cold-Weather 18650 is rated for 21 A continuous on the 3,500 mAh cell (12 A on the 4,000 mAh), so high-output flashlights get the current their top modes ask for. It is rated for use down to -40°C — built for winter EDC, search-and-rescue, and hunting in sub-freezing conditions.
The -40°C use rating is not a charging temperature range. Do not use it as permission to charge in the cold. Contact SCIGOLD for model-specific charging guidance before charging after cold-weather use.
02 · Regulated Vape Mods
Built For The Draw.
For regulated mods that take a removable 18650. Not for mechanical (unregulated) mods.
Cells run past their rated discharge are a common cause of venting, so keep your mod's draw well under the cell's continuous rating. SCIGOLD's Cold-Weather 18650 is rated for 21 A continuous on the 3,500 mAh cell (12 A on the 4,000 mAh), with the low IR (internal resistance) for less sag under load — and a built-in protected button top in case of accidental short.
03 · High-Capacity 21700
More Energy Per Cell.
21700 is the newer, larger format. Tesla's Model 3, Rivian and Lucid build with 21700-size cells, and many e-bike packs use them too.
Same form-factor philosophy as 18650, about 1.5× the volume — and about 2× the energy (5,000 vs 2,500 mAh; our Cold-Weather 18650 narrows the gap). SCIGOLD's 18,000 mWh 21700 hits the consumer sweet spot for flashlights, bike lights and work lights built for a removable 21700.
Pack building is normally done with unprotected flat-top cells and a BMS. SCIGOLD cells are protected button-tops and are not sold for building or rebuilding packs.
04 · Removable-Cell Devices
Swap The Cell. Keep Going.
Headlamps, lanterns, bike lights, battery boxes — if the cell comes out, a SCIGOLD cell can usually go in.
Many devices with a battery door or a screw-off tail cap and a removable 18650 or 21700 can run on SCIGOLD cells, and so can battery boxes and power-bank cases with spring contacts. Carry a charged spare, swap it in when the light dims, and charge the empty one on the Bench Dock. Check the device's manual for the cell it needs. They are protected button-top cells, a little longer than a bare cell, so check the device has room before you order.
And dozens more · the cylindrical Li-ion ecosystem
Battery boxes · power-bank cases
Cases with spring contacts that take loose 18650 or 21700 cells. Check that they fit a protected button-top cell.
Spotlights · searchlights
Handheld spotlights that take a removable 18650 or 21700. Check the light's manual for the cell it needs.
Camping headlamps
18650 headlamps such as the Fenix HM60R V2.0 and Nitecore HC33. Check the light's manual for the cell it needs.
Hunting · EDC flashlights
Premium 18650 cells · up to 21 A continuous for high-lumen output
Ham radio · GMRS
Some handheld radios take an aftermarket 18650 battery case. Check that it fits a protected button-top cell.
Bike lights
Front lights with a removable 21700, such as the Fenix BC26R
Camping lanterns
Lanterns that take 18650 cells, such as the Fenix CL30R. Check the lantern's manual for the cell it needs.
Work lights
Rechargeable work lights that take a 21700, such as the Fenix WT26RM. Check the light's manual for the cell it needs.
Picking By Size
Two cell sizes. Different jobs.
← Swipe the table to see every column →
| Cell size | Dimensions | Capacity range | Typical use |
|---|---|---|---|
| 18650 | 18.5–18.6 × 65.3 mm | 2,000 – 4,000 mAh / 7,200 – 13,360 mWh | Flashlights · vapes · headlamps |
| 21700 | 21.9 × 71.0 mm | 4,000 – 5,000 mAh / 14,400 – 18,000 mWh | Modern flashlights · bike lights · work lights |
Tested and certified
The SCIGOLD Catalog
Four more series to explore.
AA Rechargeable
4,440 mWh AA + Charging Case
Regulated 1.5V lithium AA that charges in the Pocket Case (CW505), an LCD charging case with USB-C input. The next AA, not the next NiMH.
USB-C Cables
60W to 240W
Liquid-silicone nightstand cables, the 240W braided flagship and a magnetic cable that coils itself.
USB-C Wall Chargers
45W to 150W
From a one-port 45W for the bag to four ports and up to 140W from one, with USB Power Delivery and PPS.
Sold out
Portable Chargers
5.5 Wh to 115.2 Wh
A lightstick battery and a 115.2 Wh power bank with 100W USB-C and a built-in jump starter, both charged over USB-C.
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