Flashlight Specifications

There are many ways to compare the features and specifications of a flashlight, and in this article, we will explain the most common of these features.

Light Output

Light output, reported in lumens, is determined by the total amount of light coming out-the-front (OTF) of the flashlight, which is related to the LED’s efficiency and how much power it uses.

  • 500+ lumens
    • Typical output of a ultra-high outputLED flashlight.
  • 250-500 lumens
    • Typical output of a high-output LED flashlight.
  • 80-250 lumens
    • Typical output of a mid-range LED flashlight.
  • 20-80 lumens
    • Typical output of a general purpose LED flashlight.

Beam Intensity

Peak beam intensity, reported in candela, represents brightness as perceived by the human eye and is related to how the beam is focused by the optical system (typically a reflector, lens, or optic). Our perception of brightness is non-linear, and for a light to appear twice as bright as another, its beam intensity has to be four times that of the other light.

  • >25,000 candela
    • Typical intensity of a tightly focused LED flashlight or spotlight.
  • 2,000-25,000 candela
    • Typical intensity of an LED flashlight.
  • <2,000 candela
    • Typical intensity of an LED worklight.

Beam Pattern (Candela/Lumen Ratio)

Beam pattern describes the relationship between light output and beam intensity. Tight beams are great for illuminating distant objects, but a bright hotspot can be blinding when used indoors, so it’s important to pick a flashlight with the right type of beam.

  • >100 cd/lm
    • Deep smooth reflectors or total internal reflection (TIR) optics produce spot beams that are optimized for outdoor use.
  • 15-100 cd/lm
    • Shallow smooth reflectors, orange-peel textured reflectors, hybrid smooth/textured reflectors, or TIR optics diffuse light into a larger hotspot.
  • <15 cd/lm
    • Shallow reflectors give off a wide area of light, which is typically found on work lights and best suited for indoor use.
  • Adjustable Focus
    • Some reflectors or optics can be adjusted for a variable spot to flood focus, but usually introduce artifacts, such as rings or holes, into the beam.

User Interface and Output Modes

LEDs can be electronically controlled for different brightness levels or output patterns. Common modes include maximum output, reduced output, strobe, or SOS.

  • Single Output
    • Simple and straightforward, click once to turn on, click once to turn off.
  • Multi-Mode
    • Different brightness levels are available and typically accessed using a series of clicks.
  • Programmable Function Sets
    • User customization allows changing the mode sequence or enabling/disabling modes.


Runtime depends on the capacity of the battery used, as well as additional factors such as whether power saving designs are used.

  • 5+ hours
    • Larger lights can house larger batteries, providing longer runtimes.
  • 1-5 hours
    • Tactical and rechargeable flashlights typically have a runtime between 1-2 hours. Some lights use step-down regulation to extend runtime,
  • < 1 hour
    • Capacitors do not store as much energy as batteries, so the 5.11 Tactical PC3.300 has a peak runtime of 13 minutes, with an option of 45 minutes from a lower output.

Power Source

Flashlight performance depends not only on the LED, but also the battery. Picking the right battery type not only provides better performance, but can also reduce the cost of operating your flashlight. Battery performance varies widely, and many are rechargeable.

  • AA/AAA
    • AA and AAA batteries are cheap and can be found anywhere, making them the battery of choice for general-purpose flashlights.
  • C/D
    • Larger batteries are heavy, and with smaller lights offering similar performance, full-sized light batons are decreasing in popularity.
  • 123A
    • 123A lithium batteries are the preferred choice for tactical lights because these batteries have twice the voltage of alkaline batteries and are about half the size.
  • Proprietary
    • Rechargeable flashlights typically use proprietary battery packs, but some of these lights can also use regular batteries.

Rechargeable lights are popular among law enforcement and professionals because they can save hundreds of dollars in purchasing disposable batteries. There are several types of rechargeable battery chemistries, each with their own advantages and disadvantages.

  • Nickel-Cadmium (NiCd, Typical Life: 1,000 cycles)
    • NiCd batteries have been around for many decades and are more robust but less energy dense than newer battery chemistries.
  • Nickel-Metal Hydride (NiMH, Typical Life: 1,000+ cycles)
    • NiMH batteries are more energy-dense and will provide more runtime than a comparable NiCd. Unless they are marketed as “low self-discharge,” stored NiMH batteries need to be recharged periodically to ensure that the light is ready to use.
  • Lithium-Ion (Li-Ion, Typical Life: 500 cycles)
    • Li-Ion batteries are smaller, lighter, and pack more power than both NiCd and NiMH, making them ideal for use in laptops and portable electronics. However, they cannot achieve as many charge cycles as nickel-based batteries and will lose capacity even if unused.
  • Capacitor (Typical Life: 50,000 cycles)
    • Capacitors are new to the scene of rechargeable flashlights, and they have significant advantages and disadvantages. While they can be charged rapidly and are lightweight, they cannot hold as much power as traditional batteries and will discharge within weeks.

Alternate Power Source (for Rechargeable Flashlights)

  • Some rechargeable flashlights can also use disposable batteries as a backup power source if the rechargeable battery is drained. These lights typically accept C-cell alkaline or 123A lithium batteries, and may require the use of a special adapter.

Size and Weight

  • Tactical-Sized (4″-6″)
    • Small and easy to carry, these lights are usually operated using a tail switch.
  • Mid-Sized (6″-10″)
    • Usually carried in a belt holster, many of these lights offer both a head and tail switch.
  • Full-Sized (10″+)
    • Large lights are usually carried in a belt loop or holster and operated using a head switch.

Charge Time (for Fully Drained Rechargeable Flashlights)

  • 90 seconds
    • Quick charge for capacitors.
  • 2-3 hours
    • Average charge time for NiCd/NiMH fast-charge rechargeable flashlight systems.
  • 3-5 hours
    • Average charge time for Li-Ion rechargeable flashlight systems.
  • 10-12 hours
    • Standard charge for NiCd/NiMH batteries, which is generally unnecessary.

Charging Options (for Rechargeable Flashlights)

  • Cradle Charge
    • Most convenient for recharging a flashlight, the cradle also provides a place to store or mount the flashlight.
  • Battery Charge
    • Allows batteries swapping, allowing the flashlight to be ready to use immediately if a charged battery is available. However, batteries must be removed from the light before charging.

Charging Power Source (for Rechargeable Flashlights)

  • 120V AC
    • Standard wall charger for North America.
  • 12V DC
    • Vehicle adapters are usually offered as an option.
  • 5V DC
    • USB charge for compact lights.

Lens/Window Material

  • Anti-Reflective Coated Glass
    • Allows maximum transmission of light, but scratches can damage the AR coating.
  • Borofloat Glass
    • High temperature glass with good transparency.
  • Anti-Scratch Coated Polycarbonate
    • Scratch-resistant, unbreakable plastic.
  • Plastic
    • Prone to scratches, which can reduce output and introduce artifacts.

Body Material/Finish

  • Type III Anodize (Hard Anodize)
    • Most durable, and also most expensive, finish for an aluminum flashlight.
  • Type II Anodize
    • Thinner finish that is not as durable as type III.
  • Polymer
    • Lightweight and preferable for cold weather, polymer is light and durable.


  • Heatsinks transfer heat away from the LED to prolong component life, and most aluminum lights use the flashlight body as a heatsink.
  • Lights with polymer bodies usually use aluminum LED modules for heatsinking, and specific spots may get warm or hot during extended operation.


  • Head Switch
    • Commonly found on larger flashlights, which are held mid-body.
  • Tail Switch
    • Commonly found on tactical-style flashlights.

Body Design

  • Cylindrical
    • Traditional looks, but round objects tend to roll around.
  • Anti-Roll
    • Some lights use an anti-roll ring, flat bezel surfaces, or asymmetrical design to prevent it from rolling around.

Bezel Design

  • Crenelations
    • When set down on a flat surface, these patterns allow light to escape through the bezel to alert the user if the light is turned on.
  • Flat
    • Simple, classic design.

Water Resistance

  • IPX4 (Water Resistant)
    • Weather resistant is typical for most flashlights.
  • IPX7 (Water Proof)
    • Submersible to 1m depth for 30 minutes.
  • IPX8 (Submersible)
    • Submersible to a specific depth (refer to manufacturer specifications) for continuous use.


  • Lifetime warranty
    • Most flashlight manufacturers provide peace-of-mind about your illumination investment. Consult the Specification Summary footnotes for additional details.
  • 3- to 5-year warranty

Build Quality

  • This opinion from our editor has a maximum score of 20 (instead of 10) in our Rechargeable LED Flashlights Comparison article.


  • Balanced between price, performance, and features. This opinion from our editor has a maximum score of 30 (instead of 10) in our Rechargeable LED Flashlights Comparison article.