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5 Different Types of Flashlight Bulbs

A flashlight with yellow bulb.

When you have a flashlight that doesn’t work anymore, the first inclination is to change the battery. After you do, if the flashlight doesn’t work anymore, it can be very frustrating. The next most common problem here is that your flashlight bulb has burned out and needs to be changed. It is easier than you think.

You don’t have to purchase a new flashlight when a new bulb will resolve the problem and give you thousands of more hours on your flashlight.

But the process can be confusing. There are many different types of flashlight bulbs.  It can be overwhelming to see the letters and numbers on all the different flashlight bulbs and not know what they mean. Wonder no more. Learn about the different flashlight bulbs right here in this comprehensive guide on flashlights.

The many different terms of flashlight power made simple

A flashlight bulb with reflector on a white background.

Flashlights are powered by the battery that runs through the electricity circuit wired in the battery that sends energy to the bulb at the end of the battery. The casing around the flashlight is the least important component of this invention, although it does provide important safety features for those using flashlights. It also functions to turn the flashlight on and off.

To make all of this work, different terms drive the flashlight’s power. The most common ones you will see when you are shopping for flashlight bulbs are:

  • Driven: The light-producing diode that transforms the electricity into light. An LED flashlight bulb can have up to 50,000
  • Xenon: A low voltage flashlight bulb made of xenon gas that produces less heat than a halogen bulb and it will also last longer. These are typically cooler bulbs.
  • Lumen: The amount of light, or splendor as it is called in the hardware store, that comes from the light bulb.
  • Watt (W): The amount of power that fuels a light bulb, the higher the wattage the brighter the light bulb. Like you traditional lamps in the house, you’ll need to know the exact wattage that your flashlight bulb needs.
  • Color Rendering Index (CRI): This functions on a scale of 1-100 and depicts exactly how much light is produced by the bulb. The higher the number, the brighter the flashlight bulb. A halogen bulb’s CRI will be 95 or more for example.

You’ll often see the terms lumens and watts interchangeably. So a 75W bulb might have 1100 lumens and be sold that way. Lightbulbs are frequently sold with the CRI listed. The general rule here is that a CRI between 50-70 is identified as Fair, 70-80 is excellent, and 80-90 is superior.

The letters on flashlight bulb packaging are confusing, if you don’t have this list

When you buy lightbulbs of any kind, there are different types that are categorized by letter combinations. Flashlight bulbs are no different. You will see letters between A and T on flashlight bulb packaging. Those letter combinations are divided into two categories. The first letter combination is for the socket shape, while the second one is for the number of pins on the lightbulb head.

These are the standard names and categories for flashlight lightbulbs.

Light Bulb Base and Socket Shape

  • A (Arbitrary)
  • B or BA (Bayonet Collar)
  • BR (Bulged Reflector)
  • C (Candle)
  • CA (California)
  • E (Edison Screw)
  • F (Single Pin)
  • G (Multiple Pin)
  • J (Iodine)
  • K (Cable Connectors)
  • MR (Multifaceted Reflector)
  • P or PS (Pear Shaped)
  • PAR (Parabotic Aluminized Reflector)
  • R (Recessed Contacts)
  • S (Shell Type)
  • T (Telephone Slide)
  • W (Wedge Base)
  • X (Special Type)

Number of Pins or Contacts (Optional)

  • s-Single
  • d-Double, bi-pin, 2-pin
  • t-Triple pin, tri-pin, or 3-pin
  • q-Quadruple pin, quad pin, 4 pin

1. Incandescent flashlight light bulbs are the most common bulbs for flashlights

A vector of different types of light bulb.

The most common kind of flashlight bulb to use is the incandescent. Incandescence refers to the kind of light that is emitted by heat, with heat being the operative component of this kind of lightbulb. When light is emitted from a warm object through radiation, the heat creates a white light that is what the bulb encasement is showing off.

The process of incandescence is thermal. And so these are going to be the hottest light bulbs that you can get. They are also going to be the most affordable because they do not use more advanced methods to create and emit light. For flashlights, this heat is generated by battery power. It is this affordability that makes them the most popular flashlight bulb.

The incandescent light bulbs are very often corrosion resistant and resistant to most weather. Waterproof encasements will help to make the incandescent light bulb even more water resistant which makes this flashlight very affordable. There is also a lot of durability built into this flashlight. That is why it is very popular for camping trips and other heavy-duty use.

2. The LED flashlight bulb has gained in popularity in recent years but is not as affordable

A small LED flashlight on a gray background.

The LED flashlight bulb is one of the most popular flashlight bulbs after the incandescent bulb. It is easily a new standard when it comes to lighting, as it is a very energy-efficient and sustainable means of lighting the home. The term LED refers to light emitting diode, a product that can produce as much as 90 percent efficiency.

In these flashlight light bulbs, a microchip is used to move the electricity. This will illuminate all light sources. The sink of the light bulb will be the area of the bulb where the heat of the electricity is absorbed. The heat sinks absorb the heat and then dissipate it into the air, which is why the light bulb never gets hot. This is, to many, the most important part of this whole story.

The purpose of LED light bulbs is to produce a longer-lasting bulb that reaches its brightness capacity in a second. These bulbs do not typically burn out like incandescent light bulbs, though. They will just get dimmer and dimmer in time, a process known as lumen depreciation.

To compare costs, an LED flashlight bulb that is small is going to be comparable in costs to an incandescent light bulb that is of the stronger or larger variety. A key difference between the two is that incandescent bulbs beam whereas LED bulbs emit light, in a fairly even way from the entire bulb.

Another key difference between the two is that the incandescent bulb can last up to two thousand hours in its lifetime, and the LED has a lifespan up to 50,000.

3. The high intensity discharge (HID) flashlight bulb uses gases to emit electricity and light

A person holding a high intensity discharge flashlight.

The high-intensity discharge (HID) flashlight bulb is one that uses gases to emit light. The electricity is run through ionized gas and to the bulb where light is emitted. The electrical current runs through an arc and between a series of electrodes in order to emit light. The types of HID bulbs for flashlights include a mercury flashlight bulb, metal halide, and sodium gas.

These are not the most popular flashlight bulbs as these bulbs are more frequently used with stage lights, outdoor lighting, and stadium events due to their brightness. They are also much more expensive than traditional flashlights that use incandescent bulbs and LED bulbs. These are also more commonly known as fluorescent lights.

4. These pressurized gas flashlights will be your krypton light

A pressurized gas flashlights bulb on a the wood.

Another kind of flashlight bulb is a flashlight bulb that uses gases like krypton and halogen to create light. Halogen or krypton bulbs in flashlights are notoriously powerful, and they are also very long-lasting. In these bulbs, a pressurized gas is used to ensure the life of the bulb lasts as long as possible.

Unlike HID flashlight bulbs, these are very affordable, and may even be as affordable as incandescent light bulbs. The pressurized light bulb ensures that the light is bright and lasts. This is what makes this bulb cost-effective for those on a budget.

The kinds of flashlights that often have these bulbs are those that require the D-volt batteries. That means that the flashlights that are bigger and may even have a handle are the flashlights that are most likely to use the pressurized gas to make a light.

5. Solar-powered flashlights are an effective means of casting a beam

Flashlights with solar power battery.

The solar-powered flashlight is a way of using the sun to create the energy needed to power a flashlight. This is another flashlight bulb that is good for the environment, and this alone will make it more popular than many other on the list. The magic behind this flashlight isn’t so much about the bulb as it is about what is powering it. In this case, it is the sun and not batteries.

It is not uncommon to find solar flashlights that are powered by both battery and the sun. Many solar-powered flashlights will come with an LED bulb, as the bulb itself can not be solar-powered. They typically come with a hand crank that generates the power after the flashlight has been in the sun or exposed to it, for a little while.

The reason that LEDs are most often used rests on the fact that they require less energy to emit light, and it takes less time to power the flashlight with the sun than with batteries.

A good solar flashlight can cast a beam up to 150 feet away, and in some cases even longer, and last for several hours at a time. Many people like these for their sustainability. With this flashlight, you don’t have batteries to throw out.

On the other hand, there is a life cycle to the rechargeable cells because these can not be replaced. So if the solar-powered flashlight is used too many times, it will have to be replaced.

Use these handy tips to maintain your flashlight so that the bulb and the batteries last as long as possible

A person placing a battery on the flashlight.

It is not uncommon to have the same flashlight kicking around your home, car, or garage for a number of years. The reason for that is that they can last a long time with the right maintenance. When you want to extend the life of your flashlight as long as possible, be sure that you keep it dry, don’t use it for anything else, and stay on top of your batteries.

A good rule of thumb for flashlight batteries is to not keep them in the tool when the tool is not in use. Instead, keep the batteries separate and in a different storage unit or compartment where you can find them easily when needed. Of course, in an emergency or power outage, you want to have a powered flashlight.

But if yours is say, a camping flashlight that only comes out once a year, or every few years, keep the batteries in storage to extend the life of the electric cells and the light bulbs. Your batteries could corrode otherwise and ruin the entire tool.

If you prefer to keep your batteries inside the flashlight, be sure that you check it every few months to see if the batteries are okay. They can corrode in time. Checking and changing the batteries as soon as possible when needed will help to extend the life of your flashlight. Store your batteries in a cool area but not the fridge or a cooling unit.

You never want to put your flashlight in water, to clean it, or for use underwater unless it is specifically designed to be submerged. You may have a waterproof flashlight that makes this feel safer but veer on the side of caution here. To clean a flashlight, use a damp cloth and wipe the dirt off of the flashlight.

If you have a waterproof or water-resistant flashlight, it is okay to get it a little bit wet. You just don’t want to submerge it at any time.

When you are not using your flashlight, don’t use it for something else. You don’t want to prop windows open with it or use it as a hammer. This could damage the interior of the encasement and its parts and render the flashlight unusable.

Frequently Asked Questions (FAQ) About Flashlight Bulbs

Q: How does a flashlight bulb fit into the flashlight?

A: There are many different components of the flashlight. There is the outer encasement is typically made of plastic. That has a switch on the outside and houses the entire unit. Inside, starting from the bottom of the flashlight is the metal spring that holds the electric cells or batteries. These cells will power the bulb. On top of the electric cells is a large contact. The flashlight bulb fits on top of that. To keep all parts inside the unit and to create an effective beam of light, a reflector sealed with a ring sits on top of the flashlight.

Q: Why is it called a flashlight?

A: The tool we call a flashlight is called a flashlight because when it was first invented, the lights appeared as flashes. The tool was invented in 1899 by David Misell. The very first flashlights were made of carbon filament bulbs and zinc batteries. Then, the light could not be kept on for a long time and so the name flashlight was born.