Yes you can.  Led capsule lamps are a popular choice for modern lighting upgrades.   This style of lamp includes G4, GY6.35 and G9 bases and they are being increasingly replaced by updated LED models.  They have a much better energy efficiency as they use less wattage to produce the same amount of light.  Not to mention they will also have a longer lifespan and warranty as well as a reduced heat output. 

What Are Halogen Capsules and Their LED Alternatives?

Halogen capsule bulbs are small light bulbs that produce light when electricity passes through a tungsten filament that is encased in a small quartz envelope filled with halogen gas. They are mostly used in decorative fixtures and low-voltage systems. 

The LED equivalent of these has the same physical form and shape but it uses LED technology instead of a filament to light up.

Key Differences Between Halogen and LED Capsules:

Can I Put LED Bulbs in Halogen Fittings?

Yes you can but you will need to review the technical specifications to make sure they are compatible.  If you do not have previous to compare this to you can the details on the fixture they are going into should give you the information you need.  

Low-Voltage vs. Mains-Voltage Fittings

Halogen capsules fall into two main categories: low-voltage and mains-voltage.

1. Low-Voltage (12V) Halogen Fittings (G4, GY6.35, etc.)

12V halogen systems require a transformer to step down 240V mains household voltage down to 12V.  When you are replacing these halogen bulbs with LEDs it is important to check the transformer/driver it is unlikely that it will be compatible with LED bulbs due to their lower use of wattage. 

Halogen transformers will have a minimum load requirement (such as 20W) to function. Since LED capsules use a lot less power (such as 2W),  if you try to use the LED bulbs in the same system the total load on the transformer will fall below the minimum.  This will cause the transformer to flicker or hum and the LED may not turn on at all.  To get around this you will need to replace the transformer with an appropriate LED driver.  It is worth noting that if you are looking to dim the light you will need to make sure it is a dimmable LED driver that you choose.

2. Mains-Voltage (240V) Halogen Fittings (G9, etc.)

Mains-voltage capsules, such as a G9 lamp, do not require a separate transformer as they operate on mains voltage.  This means that they can be changed to LEDs with minimal hassle.  We would recommend that you check the size as LEDs can sometimes be larger and to measure the space within the light fixture to make sure they will fit once you know the size.

Dimmer Switch Compatibility

If your halogen fitting is connected to a dimmer switch, you will need to make sure the LED replacement is labelled as dimmable.  You will also need to make sure that the driver you use is also labelled as dimmable, paying attention to what kind of dimming is required.  This should be advised on the manufacturer's details for the dimmer switch and will likely say something like “trailing edge” or “0-10V dimming.”

What are the Benefits of Switching to LED Halogen Replacements?

Switching from halogen capsules to LEDs has number of great benefits:

1. Massive Energy Savings

LED capsules consume up to 90% less energy when compared to halogen bulbs.  A typical 25W halogen G9 bulb for example can be replaced by a 2.5W LED G9 that will have the same brightness.  This will lead to noticeable savings on your energy bills.  

2. Reduced Fire and Burn Risk

Halogen capsules operate at extremely high temperatures in order to light up, sometimes in the hundreds of degrees Celsius.  This poses a potential burn hazard and will increase fire risk if placed near anything flammable.  LED capsules remain cool to the touch thanks to their heatsink meaning they do not post this same risk.

3. Longer Lifespan

LEDs can last 15 to 25 times longer than most halogen bulbs. This means less time is spent needing to replace them.  They will also have a higher manufacturers warranty meaning you are covered if they do not last as they should which again leads to reduced costs.

4. Color and Design Versatility

LED capsules lamps are available in a range of color temperatures ranging from very warm white (2700K) to daylight (6000K).  This gives you a larger variety of options to choose the light that suits the environment best.