Nitecore NL1840R: a 4,000mAh 18650 battery you charge with a USB-C cable

Nitecore has launched the NL1840R, an 18650 lithium-ion battery with a built-in USB-C charging port, meaning you can top it up with the same cable you use for your phone. The cell delivers 4,000mAh (14.4Wh) — close to the practical ceiling for the 18650 format — and ships now through Nitecore's own storefront and specialist flashlight retailers in the US and UK.

The built-in port

The USB-C port sits at the top of the cell. A two-color LED indicator shows charging status: red while charging, green when done. If you already own an external Nitecore charger — the UMS4, UMS2, Ci4, or Ci2 — the NL1840R works with those too. The port is an addition, not a replacement.

Nitecore rates the cell for 500 or more full charge cycles with at least 80% capacity retained. That's the standard benchmark for quality lithium-ion, though real-world lifespan depends heavily on how you store it and whether you regularly drain it to zero. Energy density comes in at 288mWh/g, which Nitecore claims is 17.6% better than conventional 18650 cells.

The length problem

Here's the practical issue: the NL1840R is 71mm long. A standard unprotected 18650 is around 65mm. That extra 6mm — housing the USB-C hardware — means the battery won't fit every device that takes an 18650. Flashlights with dual-spring battery compartments or tight tube designs are the most likely to reject it. Measure your torch before buying.

This isn't a minor footnote. Plenty of people own compact or older flashlights that simply won't accommodate the extra length. It's the same tradeoff that applies to any protected 18650 cell, but worth calling out clearly.

The price and competition

Nitecore hasn't published an official price for the NL1840R yet. The predecessor, the NL1840HP (no USB-C port), sells for $23.95 in the US — roughly £19 in the UK. A premium for the built-in port is expected, with Singapore retail listings suggesting a final price in the $30–35 range.

The competition is real. Streamlight's BL26 and KeepPower's USB-C 18650 cells already sit in this space. Nitecore's strongest argument isn't the cell tech itself — it's the broader charger ecosystem. If you're already running Nitecore gear, the NL1840R fits cleanly into the setup. If you're buying your first USB-C 18650, the options are wider than they used to be.