1. Introduzione
The Nitecore E4K is a high-performance, compact Everyday Carry (EDC) flashlight designed for versatility and power. It features four CREE XP-L2 V6 LEDs, delivering a maximum output of 4400 lumens and a beam distance of up to 211 meters. This manual provides detailed instructions for the proper use, maintenance, and care of your Nitecore E4K flashlight.

Image 1.1: The Nitecore E4K flashlight, showing its compact design, USB-C charging cable, and included battery organizer.
2. Contenuto della confezione
Please inspect the package contents upon receipt to ensure all items are present:
- Nitecore E4K Flashlight (NL2150HPR battery pre-installed)
- Cavo di ricarica USB-C
- Two-way Metal Pocket Clip
- Fondina
- cordino
- LumenTac Storage Case

Image 2.1: All items included in the Nitecore E4K package.
3. Caratteristiche del prodotto
- Uscita potente: Utilizes 4 x CREE XP-L2 V6 LEDs for a maximum output of 4400 lumens.
- Design compatto: Weighs 2.82 ounces and measures less than 5 inches, ideal for everyday carry.
- USB-C ricaricabile: Integrated USB-C charging port on the battery for convenient recharging.
- Interfaccia intuitiva: Single side switch controls five brightness levels and three special modes.
- Regolazione avanzata della temperatura (ATR): Automatically adjusts output to prevent overheating.
- Costruzione durevole: Constructed from anodized aluminum with an IP68 waterproof rating (2 meters submersible) and 1-meter impact resistance.
- Capacità di appoggio della coda: Allows the flashlight to stand upright for hands-free illumination.
- Precision Digital Optics Technology (PDOT): Ensures optimal reflector performance.

Image 3.1: Key design elements of the Nitecore E4K, including knurling for grip, cooling fins for heat dissipation, and tail stand capability.
4. Specifiche
| Caratteristica | Dettaglio |
|---|---|
| Uscita massima | 4400 lumen |
| Distanza massima del raggio | 211 metri |
| Intensità massima del raggio di picco | 11100 dollari |
| LED | 4 LED CREE XP-L2 V6 |
| Tipo di batteria | 1 x 21700 Li-ion (NL2150HPR included) |
| Porta di ricarica | USB-C (a batteria) |
| Dimensioni | Length: 117.56 mm (4.63"), Head Diameter: 28.6 mm (1.13"), Tail Diameter: 28.1 mm (1.11") |
| Peso | 80 g (2.82 oz) (senza batteria) |
| Resistenza all'impatto | 1 metro |
| Grado di impermeabilità | IP68 (sommergibile 2 metri) |
| Materiale | Aero grade aluminum alloy with HA III military grade hard-anodized finish |

Image 4.1: Physical dimensions and weight of the Nitecore E4K flashlight.

Image 4.2: Detailed technical specifications for the Nitecore E4K across various modes.
5. Installazione e ricarica della batteria
5.1 Installazione della batteria
- Svitare il tappo posteriore in senso antiorario.
- Insert the included Nitecore NL2150HPR 21700 Li-ion battery with the positive (+) terminal facing the head of the flashlight.
- Riavvitare il tappo posteriore in senso orario fino a quando non è ben stretto.
Nota:
- Ensure the battery is inserted correctly to prevent damage from reverse polarity.
- The flashlight may not function if the tail cap is not fully tightened.
5.2 Caricamento della batteria
The Nitecore E4K utilizes a specialized NL2150HPR 21700 battery with an integrated USB-C charging port. This allows for convenient charging without needing an external charger.
- Unscrew the tail cap and remove the NL2150HPR battery.
- Locate the USB-C charging port on the side of the battery.
- Connect the provided USB-C charging cable to the battery's port and plug the other end into a USB power source (e.g., phone charger, computer USB port).
- During charging, a red indicator light on the battery will illuminate. It will turn green when charging is complete.
Indicatori dello stato di carica:
- Luce rossa: Ricarica in corso.
- Luce verde: Ricarica completata.

Image 5.1: The Nitecore E4K battery being charged via its integrated USB-C port.
6. Istruzioni per l'uso
The Nitecore E4K features a single side switch for all operations. Familiarize yourself with the following actions:
6.1 Funzionamento generale
- Attiva: When the light is off, press and hold the side switch for approximately 1 second to turn it on.
- Spegnere: When the light is on, press and hold the side switch for approximately 1 second to turn it off.
- Regolazione della luminosità: When the light is on, short press the side switch to cycle through brightness levels: Ultralow → Low → Mid → High → Turbo. The flashlight has mode memory and will turn on at the last used brightness level (excluding Turbo and special modes).
6.2 Modalità di accesso diretto
- Direct to Ultralow: When the light is off, double-press the side switch to directly access Ultralow mode.
- Turbo momentaneo: When the light is on, press and hold the side switch to access Turbo mode. Release the switch to return to the previous brightness level.
6.3 Modalità speciali (strobo, SOS, faro)
- Access Special Modes: When the light is on or off, triple-press the side switch to enter Strobe mode.
- Cycle Special Modes: While in Strobe mode, short press the side switch to cycle through Strobe → Beacon → SOS.
- Exit Special Modes: Press and hold the side switch for approximately 1 second to turn off the flashlight, or short press to return to the previously memorized brightness level (if entered from an 'on' state).
6.4 User Modes (Daily Mode / Tactical Mode)
The E4K offers two user modes: Daily Mode (default) and Tactical Mode. To switch between modes:
- Ensure the flashlight is off.
- Unscrew the tail cap slightly.
- Press and hold the side switch while simultaneously tightening the tail cap.
- The flashlight will flash once to indicate Daily Mode or twice to indicate Tactical Mode. Release the switch after the desired mode is indicated.
Mode Differences:
- Modalità giornaliera: Triple-press from off directly accesses Turbo.
- Modalità tattica: Triple-press from off directly accesses Strobe.

Image 6.1: Visual guide to the Nitecore E4K's user interface and button functions.
7. Indicazione del livello della batteria
The E4K provides two methods to check the battery level:
7.1 Detailed Voltage Lettura
When the tail cap is loose and then tightened, the blue indicator light under the side switch will flash to show the battery voltage (preciso fino a ±0.1V). Ad esempioample, three flashes followed by a pause and then two flashes indicates 3.2V.
7.2 Quick Power Indication
When the flashlight is off, short press the side switch. The blue indicator light will flash to indicate the remaining battery power:
- 3 flash: Battery power above 50%.
- 2 flash: Battery power between 10% and 50%.
- 1 Flash: Battery power below 10%.

Image 7.1: The blue indicator light on the side switch displays battery level.
8. Advanced Temperature Regulation (ATR)
The Nitecore E4K incorporates an Advanced Temperature Regulation (ATR) module. This technology automatically adjusts the flashlight's output based on its working condition and ambient environment to maintain optimal performance and prevent overheating. This ensures the longevity of the flashlight and the safety of the battery.
9. Manutenzione
- Pulizia: Pulisci il corpo della torcia con un panno morbido eamp panno. Per lo sporco ostinato, è possibile utilizzare una soluzione di sapone delicato. Evitare prodotti chimici aggressivi o materiali abrasivi.
- Lubrificazione: Lubricate the O-rings and threads regularly with silicone grease to maintain waterproof sealing.
- Cura della batteria: Store the battery in a cool, dry place. Recharge the battery every 3 months if not in regular use to prolong its lifespan.
- Punti di contatto: Keep all electrical contact points clean. If the flashlight does not turn on or respond, clean the battery contacts and the flashlight's contact points with an alcohol swab.
10. Risoluzione Dei Problemi
- La torcia non si accende:
- Ensure the battery is inserted correctly with the positive (+) terminal facing the head.
- Verificare che il tappo posteriore sia completamente serrato.
- Controlla se la batteria è carica.
- Clean battery contacts and flashlight contact points.
- Output decreases or flashlight gets hot quickly:
- This is normal behavior for high-output flashlights, especially in Turbo mode, due to the ATR system. The flashlight reduces output to prevent overheating.
- Ensure adequate airflow around the flashlight during prolonged high-output use.
- Ingresso d'acqua:
- Check if O-rings are properly seated and lubricated.
- Assicurarsi che il cappuccio della coda sia completamente serrato.
11. Informazioni sulla garanzia
Nitecore products are covered by a manufacturer's warranty. For detailed warranty terms and conditions, please refer to the official Nitecore website or contact your local distributor. Please retain your purchase receipt for warranty service.





