NITECORE NL1840R (18650 - 4000MAH - 6A)

An 18650 that charges itself, straight from any USB-C cable.

A 4,000mAh protected 18650 with a built-in USB-C port, so a power bank or a phone charger tops it up with no separate charger needed.

• 4,000mAh, 3.6V, 14.4Wh of energy, roughly four times a CR123A
• Built-in USB-C port charges directly from a cable or a power bank
• Red light while charging, green when it is full
• 6A maximum continuous discharge for high-drain lights
• Intelligent protected circuit plus a pressure-relief valve for safety
• Rated for over 500 charge cycles, keeping more than 90% capacity
• The exact cell that powers the Nitecore UT6 headlamp

Charge it with the cable already in your bag.

The USB-C port is built into the cell itself, so a wall charger, a laptop or a power bank brings it back to full. Pack one cable for your phone and the same one tops up this battery.

A small light on the cell tells you where you stand. Red stays on while it charges, and it turns green the moment it is full, so you can leave it and check at a glance.

Two ways to charge, whichever suits the day.

Charge it in place over USB-C when you are travelling light, or drop it into a Nitecore charger when you are topping up a few cells at home. Both routes get you to a full battery.

On the trail or in a hotel room, plug it into a power bank and keep moving. The flexibility means you are never tied to one charger or one socket.

4,000mAh, about four times a CR123A.

With 4,000mAh and 14.4Wh on board, this cell holds roughly four times the energy of a single CR123A. That is longer runtime per charge in a compatible light, and fewer swaps on a long night out.

The 6A maximum continuous discharge keeps high-drain lights fed at their brighter modes, so the output you bought for is the output you get.

WHY A SELF-CHARGING CELL OVER A STANDARD 18650 PLUS CHARGER

No separate charger to pack

The USB-C port is in the cell, so any cable you already carry tops it up. A standard 18650 needs its own dock to come back to life.

Top up from a power bank

Run a cable from a pocket power bank and refill it anywhere. An ordinary cell waits until you are back at a mains socket.

Protected and built to last

An intelligent protected circuit, a pressure-relief valve and steel end protectors guard every charge. Many bare cells ship with none of this.

A charge state you can read

The red and green indicator shows charging and full at a glance, so you load a known-full cell. A plain battery leaves you guessing.

A MULTI-LAYER PROTECTION SYSTEM

Inside the cell sits an intelligent protected circuit built around a purpose-designed, high-performance protection IC. It guards against overcharge, over-discharge and short-circuit, while a high-power MOS-FET regulates current under load.

The result is steady, dependable power on every cycle, whether the cell is feeding a bright light or sitting on charge overnight.

Built-in safeguards, inside and out.

A pressure-relief valve responds to a rapid rise in temperature, releasing internal pressure to keep the cell stable in demanding use. It is the kind of safeguard you want and rarely think about.

Together with the protected circuit, these internal features mean the battery looks after itself through hard use and long storage alike.

A tough shell that handles daily carry.

Nickel-plated stainless-steel protectors cap both ends of the cell, shielding the contacts from knocks and wear in a pack or a pocket. A durable metallic film wraps the body to resist abrasion.

It is a cell that takes the rough handling of everyday carry and keeps a clean, reliable connection in your light.

Over 500 cycles, with energy to spare.

Rated for more than 500 full charge cycles, this cell still holds over 90% of its capacity after 500 rounds. Charge it most days and it keeps delivering for a long time before it fades.

It is made mercury-free, lead-free and cadmium-free, so a long-life battery is also a cleaner one to live with and dispose of.

WHERE THE NL1840R EARNS ITS PLACE

Flashlight Owners

A high-capacity 6A cell that keeps a compatible 18650 light running bright, then recharges from any USB-C cable.

Headlamp & UT6 Owners

The exact cell that powers the Nitecore UT6 headlamp, ready to refill hands-free over USB-C between runs.

EDC & Preparedness

A protected spare you can keep topped up from a power bank, ready in a kit or a go-bag using just a USB-C cable.

Travelling Light

Leave the charger at home and refill the cell in place, using the same USB-C cable that charges your phone.

Drops into your Nitecore chargers.

When you prefer a dock, the NL1840R works in the Nitecore UMS4, UMS2, Ci4 and Ci2 chargers. Charge it alongside your other cells in a multi-bay charger at the bench.

So you have it both ways. Charge in place over USB-C when you are out, or top up a row of cells in a charger when you are home.

SPECIFICATIONS

Chemistry: Li-ion (protected 18650, button-top)

Capacity: 4,000mAh

Nominal Voltage: 3.6V

Energy: 14.4Wh

Max Continuous Discharge: 6A

Charging: Built-in USB-C port, or external charger

Charge Indicator: Red charging / green full

Protection: Intelligent protected circuit, pressure-relief valve, steel end protectors

Cycle Life: >500 cycles, >90% capacity retained

Dimensions: 18.5mm ±0.3 dia × 71.0mm ±0.3 length

Weight: 51g

COMPATIBLE CHARGERS & CERTIFICATIONS

Compatible Chargers: Nitecore UMS4, UMS2, Ci4, Ci2

Direct Charging: Any USB-C cable, including from a power bank

Materials: Mercury-free, lead-free, cadmium-free

End Protectors: Nickel-plated stainless steel, both ends

Body Wrap: Durable metallic anti-abrasion film

Certifications: CE and further global certifications

Sold per UNIT.