If your Photon Micro-Light II just doesn’t seem as bright as it once did, it may be time to change the batteries.

Unlike traditional flashlights using alkaline batteries, you won’t see a sharp decline in brightness to signal a dead battery. Lithium coin-cell batteries have a very flat discharge curve, meaning that as the batteries are depleted you will get a very gradual reduction in brightness over the entire life of the batteries rather than a sudden drop at any point. Because of this, deciding when the batteries are “dead” and need to be replaced is often a matter of personal preference. If you find yourself thinking that your light doesn’t seem to be as bright as it once was, it might be time to replace the batteries.

The same solid construction that makes the Photon II so durable also makes the battery replacement slightly more involved than many of Photon’s other keychain lights. If you have any difficulties replacing your batteries, please feel free to contact customer service and we will be happy to provide assistance.

Also, one hint if you are looking to extend the battery life and don’t need the absolute brightest possible light — Any Photon II which normally uses the pair of smaller CR2016 batteries (i.e. White, Blue, Green, Turquoise & Purple) *can* run on a single CR-2032 battery instead if you wish. This will reduce the brightness substantially, but will greatly increase the run-time.


Photon Micro-Light II Battery Replacement Instructions:

Depending on the beam color, your Photon II will use either a pair of lithium CR-2016 batteries (white, green, NV green/turquoise, blue, & purple) or a single CR-2032 lithium battery (red, orange, yellow, & infrared). Replacement with CR-2016 batteries pictured to right. Photon Micro-Light II battery replacement illustration

A detailed PDF file showing step-by-step Photon II battery replacement is available here.

  1. Remove four screws from bottom of the Photon and flip case over so switch is on top. Note: Press firmly with screwdriver to avoid damage to screw or driver tip.
  2. Carefully separate top and bottom case.
  3. Remove clear slide switch.
  4. Hold bulb down with one finger and lift lead (wire) just enough to remove batteries.
    Important! Do NOT change bulb leads except for raising enough to replace batteries.
  5. Install new battery(s).
  6. Replace slide switch on slightly raised lead.
  7. Position top case so slide switch extends through hole and close case.
  8. Flip over and replace screws.

*Note: It is common for the Photon II to turn on during reassembly.  If your Photon II remains turned on after reassembly, simply squeeze the button and it should turn off.

*For best performance we recommend Energizer brand replacement batteries.