Operating Instructions
Mode Switching
In any state, turn the tail toggle switch to select the needed mode. Turn the toggle switch to the left end to enter the White light mode, turn the toggle switch to the right end to enter the Red light mode, and to the middle to enter the Lockout/off mode.
Lockout/off mode: Turn the toggle switch to the Lockout/off mode to instantly turn off the flashlight. The dual tail switch will not response to any operation.
On/off
With the light turned off and unlocked:
- Tap the tactical switch to turn on the light momentarily, release it and the light will go out.
- Fully press the tactical switch to constantly turn on the light, and fully press it again to turn off the light.
- With the light turned on, turn the toggle switch to the Lockout mode to turn off the light.
Instant Turbo
With the light turned off and unlocked, fully press the tactical switch for 0.5 seconds to activate and maintain Turbo. Single click the functional switch to switch to the lowest output or fully press the tactical switch to turn off the light.
Strobe/Red Flash
Note: Operations in White light mode correspond to Strobe. Operations in Red light mode correspond to Red flash.
With the light turned on, press and hold the functional switch for 0.5 seconds to enter Strobe/Red flash. Single click the functional switch or tap the tactical switch to recall the previously used output.
With the light turned off and unlocked, press the functional switch to enter Strobe/Red flash, release it and the light will go out.
Output Selection
White light mode: With the light turned on, single click the functional switch to cycle through Eco→Low→Med→High→Turbo.
Red light mode: With the light turned on, single click the functional switch to cycle through Red light(Low)→Red light(Med)→Red light(High).
Intelligent Memory Circuit
The flashlight automatically memorizes the last selected output excluding Strobe and Red flash.
Battery Specification
Type | Dimensions | Nominal Voltage | Usability | |
Fenix ARB-L18-4000 | 18650 | 3.6 V | Recommended | √√ |
Fenix-L18-3400/Fenix-L18-3500 | 18650 | 3.6 V | Usable | √ |
Other Fenix-L18 Series batteries | 18650 | 3.6V | Banned | × |
Warning:
- Do not use a 21700 or 16340 battery.
- Do not mix batteries of different brands, sizes, capacities, or types.
*18650 Li-ion batteries are powerful cells designed for commercial applications and must be treated with caution and handled with care. Using low-quality batteries or mishandling batteries (such as short-circuiting or overheating) could lead to combustion and jeopardize the safety of users and property. Any adverse effects resulting from the use of low-quality batteries are not covered by any Fenix warranty or liability. Using quality batteries with circuit protection will reduce the potential for combustion or explosion.
Battery Replacement
Open the battery loader and insert the batteries with one battery’s anode terminal (+) towards the light head and the other’s cathode (-) towards the light head, then close the battery loader.Once the battery compartment is closed, slide the battery latch to lock it in place and prevent it from accidentally opening.
Charging
Slide the port cover to reveal the charging port, then connect the USB Type-C end of the charging cable to the flashlight.
The battery level indicator will display red while charging and will turn green when fully charged.
When charging fails or the batteries are reversely connected, the battery level indicator will flash red or remain off to remind users to check the batteries.
This flashlight supports fast charging and can be fully charged in just 1.5 hours when charged with a 9 V/3 A charging adapter. When charged with a 5 V/3 A charging adapter, the charging time will be approximately 3 hours from depleted to fully charged.
Note:
Recharge a stored flashlight every four months to maintain the optimum performance of the battery.
This flashlight can be operated while charging.
Battery Level Indication
Each time the flashlight is turned on, the battery level indicator will indicate the battery level and will last for 3 seconds.
- Green light on: saturated 100% - 85%
- Green light flashes: sufficient 85% - 50%
- Red light on: poor 50% - 25%
- Red light flashes: critical 25% - 1%
Note: This only works with a Fenix ARB-L18 Series rechargeable battery.
Intelligent Overheat Protection
The flashlight will accumulate a lot of heat when used at high output levels for extended periods. When the flashlight reaches a temperature of 60°C/140°F or above, it will automatically step down a few lumens to reduce the temperature. When the temperature drops below 60°C/140°F, the flashlight will gradually recall the preset output level.
Low-voltage Warning
When the battery level is too low, the battery level indicator blinks red to remind users to recharge or replace the batteries in a timely manner.
Note: This only works with a Fenix ARB-L18 Series rechargeable battery.
Usage and Maintenance
- Disassembling the sealed head can cause damage to the flashlight and will void the warranty.
- Fenix recommends using excellent quality batteries.
- If the flashlight will not be used for an extended period, remove the batteries, or the flashlight could be damaged by electrolyte leakage or explosion.
- Turn off and lock the flashlight or remove the batteries to prevent accidental activation during storage or transportation.
- Long-term use can result in O-ring wear. To maintain a proper water seal, replace the ring with an approved spare.
- Periodic cleaning of the flashlight and battery contacts improves the flashlight's performance as dirty contacts may cause the flashlight to flicker, shine intermittently or even fail to illuminate for the following reasons:
A: Poor battery level.
Solution: Recharge or replace the batteries. (Ensure the batteries are inserted according to the manufacturer’s specifications).
B: The contact or contact point of the battery or flashlight is dirty.
Solution: Clean the contact points with a cotton swab soaked in rubbing alcohol.
If the above methods don't work, please contact the distributor.
Warning
- Do NOT place this flashlight in the reach of children!
- Do NOT shine this flashlight directly into the eyes of anyone!
- Do NOT place light head near flammable objects, high temperatures can cause objects to overheat and become flammable/ignite!
- Do NOT use this flashlight in inappropriate ways such as holding the unit in your mouth, doing so could cause serious personal injury or death if the light or internal batteries fail!
- This flashlight will accumulate a significant amount of heat while operating, resulting in a high temperature of the light shell. Pay close attention to avoid burns!
- Turn off and lock the flashlight or remove the batteries to prevent accidental activation when the flashlight is placed in a closed and flammable environment such as pockets and backpacks!
- The LEDs of this flashlight are not replaceable; so the whole flashlight will need to be replaced when any one of the LEDs reaches the end of its lifespan!


