Most often it’s a depleted battery or a battery that isn’t seated correctly. Charge the battery fully using a USB-C cable and charger, then reinstall it, making sure the positive (+) end is oriented as shown in your manual. On the XP40, also check that Safety Lock isn’t engaged, since it disables the switch to prevent accidental activation. Refer to your manual for how to unlock it. If it still won’t turn on, contact our support team, or file a warranty claim if you think it’s defective.

This is usually low battery voltage, a loose battery connection, or thermal step-down — many high-lumen modes automatically reduce brightness to prevent overheating during extended use. Try reseating the battery first; if it persists, it may need charging.

Start with the cable and adapter, not the light — swap to a different USB-C cable or port to rule those out first. If the charging LED still won't light up, check the port for lint or corrosion and clean gently with a dry, soft brush.

All four lights use the Zero-Hesitation Interface: a dominant switch for Turbo and a secondary switch for other modes. The XP40’s controls are side-mounted toggle/touch switches, and its Safety Lock must be disengaged first.

For step-by-step button presses, open the manual on your model’s product page: X14, X16, X30, XP40.