On/Off
Tap the tail switch to momentarily activate the light (release and the light will go out), fully press to constantly activate the light, then press again to turn off the light.
Output Selection for the HT18
With the light switched on, single click the side switch to cycle through Low→Med→High→Turbo.
Strobe
With the light switched on, press and hold the side switch for 0.8 seconds to enter strobe, single click the side switch again to turn back to the previously used general mode.
HT18 Intelligent Memory Circuit
The light memorizes the last selected brightness level on general mode (excluding strobe). When turned on again the previously used brightness level will be recalled.
Battery Specifications
| Type | Dimensions | Nominal Voltage | Recommended |
| Rechargeable Li-ion Battery | 21700 | 3.6V | Fenix ARB-L21 Series |
| Rechargeable Li-ion Battery | 18650 | 3.6V | Fenix ARB-L18 Series |
Warning:
- The Fenix dedicated ALF-18 battery holder must be used together when using 18650 Li-ion battery.
- Do not use CR123A or 16340 battery. Doing so may cause damage to the flashlight or the battery being used.
*18650 /21700 Li-ion batteries are powerful cells designed for commercial applications and must be treated with caution and handled with care. Only using quality batteries with circuit protection will reduce the potential for combustion or explosion; but cell damage or short circuiting are potential risks the user assumes.
Battery Replacement of HT18
Unscrew the tail cap and insert the battery with the anode side (+) towards the light head, then screw the tail cap back on.
Battery level indication
When the light is switched on, the battery level indicator inside the side switch will light up to display the battery status, the indicator will stay on for 3 seconds before it goes off.
- 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 Fenix ARB-L21 Series 21700 and Fenix ARB-L18 Series 18650 rechargeable Li-ion battery.
Intelligent Protection
The light will accumulate a lot of heat when used on Turbo output level for extended periods. When the light reaches a temperature of 65°C or above, the light will automatically step down by a few lumens to reduce temperature, until it reaches the output of 800 lumens. When the temperature has been reduced, the output will gradually return to Turbo. Note: The above data is the test results given by Fenix through its laboratory testing. The true performance may vary according to different working environments.
Low-voltage Warning
When the voltage level drops below the preset level, the flashlight is programmed to downshift to a lower brightness level until Low output is reached. When this happens in Low output mode, the indicator in the mid of the side switch will flash red to remind you to recharge or replace the battery. To ensure normal use, the flashlight will not turn off automatically and will work till the battery runs out completely. Note: This only works with Fenix ARB-L21 Series 21700 and Fenix ARB-L18 Series 18650 rechargeable Li-ion battery.
Usage and Maintenance of the Fenix HT18 Long Distance Hunting Flashlight
- Disassembling the sealed head can cause damage to the light and will void the warranty.
- Fenix recommends using an excellent quality battery.
- If the light will not be used for an extended period, remove the battery, or the light could be damaged by electrolyte leakage or battery explosion.
- Li-ion battery needs to be charged even if the battery is not exhausted, charge immediately when the battery is exhausted; it has no memory effect.
- Unscrew the tail cap half a turn or take out the battery 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 battery contacts improves the lamp's performance as dirty contacts may cause the lamp to flicker, shine intermittently or even fail to illuminate for the following reasons:
A: The battery needs replacing.
Solution: Replace battery (Ensure battery is inserted according to the manufacturer’s specifications).
B: The threads, PCB board contact or other contacts are dirty.
Solution: Clean the contact points with a cotton swab soaked in rubbing alcohol.
If the above methods don't work, please contact your authorized distributor.
Warning
- This flashlight is a high-intensity lighting device capable of causing eye damage to the user or others. Avoid shining the flashlight directly into anyone’s eyes.
- This flashlight will accumulate a lot of heat when used for extended periods, resulting in high temperature of the flashlight shell. Pay attention to safe use to avoid scalding.
