Can I charge this battery in a standard 21700 charger?

No. This battery charges only through the Nitecore R40 v2 flashlight, either via the light's USB-C port or using the two charging docks that ship with the R40 v2. It will not work in third-party charging bays.

Will this battery fit other flashlights that take 21700 cells?

No. The DW series batteries are engineered to work exclusively with the Nitecore R40 v2 and will not function in other lights, even if they physically accept 21700 format cells.

What does 'used' condition mean for this battery?

The battery has been previously owned and charged. Lithium-ion cells degrade with charge cycles, so expect somewhat reduced capacity compared to a new cell. The merchant does not specify remaining capacity or cycle count.

How long does it take to charge this battery?

Charge time depends on the power source connected to your R40 v2's USB-C port or docking station. Nitecore does not publish specific charge duration for this 5000mAh cell.

Does this battery come with any warranty or insurance?

The merchant notes the battery is globally insured and carries multiple electronic safety certifications, but does not detail warranty terms for used units. Contact the seller for coverage specifics.

Nitecore NL2150DW 5000mAh Customized Rechargeable Battery for the R40 v2 - Used

#5 in Tools & Gear

stainless steel
rechargeable

The 3-second version

5000mAh capacity in the 21700 format for extended runtime
Works only with the Nitecore R40 v2 flashlight
Charges through the R40 v2's USB-C port or included docks
Only compatible with Nitecore R40 v2
Must charge via R40 v2—no standalone charger works
Listed as used condition

Why it's on GiftsFeed

21700 Rechargeable Battery Custom-Built for the Nitecore R40 v2

Most spare batteries force you to carry a charger or swap them into a dock. This one charges through the flashlight you already have with you, using the USB-C port or the docking stations that came with the R40 v2. That saves pocket space and simplifies the routine when you need to top off a spare.

The limitation is real: this cell cannot live in any other light, and it will not accept charge from a third-party bay. For R40 v2 users, that exclusivity buys drop-in compatibility and peace of mind that the battery and light were designed together. For anyone else, it is a non-starter.

Good gift when

Nitecore R40 v2 owners who need a backup or replacement cell
Security or patrol work requiring long uninterrupted runtime
Anyone who wants a spare battery without carrying a separate charger

Skip it if You own a different flashlight model—this battery only works with the R40 v2, and you cannot charge it outside that light's ecosystem.

Specs

Capacity: 5000mAh
Format: 21700
Chemistry: Lithium-ion
Compatibility: Nitecore R40 v2 only
Charging method: Via R40 v2 USB-C port or included docking stations
Terminal material: Nickel-plated stainless steel
Safety features: Pressure relief valve, overcharge/over-discharge/short-circuit protection
Condition: Used

If you're giving it

No sizing to guess

Only useful if the recipient already owns a Nitecore R40 v2 flashlight.

The details

This rechargeable lithium-ion battery delivers 5000mAh in the 21700 format, engineered to work only with the Nitecore R40 v2 flashlight. That exclusivity is the trade-off for seamless compatibility: it charges directly through the R40 v2's USB-C port or via the docking stations that ship with the light, and it fits the housing without adapters or guesswork.

The construction uses nickel-plated stainless steel terminals that resist corrosion and impact while maintaining consistent conductivity. A built-in pressure relief valve and high-temperature resistant design address thermal stress, and the onboard safeguards monitor for overcharge, over-discharge, and short circuits. These protections work together with the R40 v2's own charging logic.

You charge this battery through the flashlight itself—no separate charger is compatible. That keeps your kit simple if you already own the R40 v2, but it means you cannot use a third-party charging bay or swap this battery into other lights. The 5000mAh capacity extends runtime significantly beyond older 18650 cells, making it practical to carry a spare for extended use in the field or on overnight shifts. Globally insured with multiple electronic safety certifications.

Nitecore

Nitecore NL2150DW 5000mAh Customized Rechargeable Battery for the R40 v2 - Used

5000mAh capacity in a format that works exclusively with your R40 v2 flashlight

$15.96$19.9520% offat nitecorestore.com

Quantity

Ships and sold by Nitecore. About this merchant

The 3-second version

5000mAh capacity in the 21700 format for extended runtime
Works only with the Nitecore R40 v2 flashlight
Charges through the R40 v2's USB-C port or included docks
Only compatible with Nitecore R40 v2
Must charge via R40 v2—no standalone charger works
Listed as used condition

Cheaper alternatives

Leatherman OPNR$10

Questions

Can I charge this battery in a standard 21700 charger?: No. This battery charges only through the Nitecore R40 v2 flashlight, either via the light's USB-C port or using the two charging docks that ship with the R40 v2. It will not work in third-party charging bays.
Will this battery fit other flashlights that take 21700 cells?: No. The DW series batteries are engineered to work exclusively with the Nitecore R40 v2 and will not function in other lights, even if they physically accept 21700 format cells.
What does 'used' condition mean for this battery?: The battery has been previously owned and charged. Lithium-ion cells degrade with charge cycles, so expect somewhat reduced capacity compared to a new cell. The merchant does not specify remaining capacity or cycle count.
How long does it take to charge this battery?: Charge time depends on the power source connected to your R40 v2's USB-C port or docking station. Nitecore does not publish specific charge duration for this 5000mAh cell.
Does this battery come with any warranty or insurance?: The merchant notes the battery is globally insured and carries multiple electronic safety certifications, but does not detail warranty terms for used units. Contact the seller for coverage specifics.