How to Power Outdoor Christmas Lights: Solar, Battery, and No-Outlet Options

Introduction

If you want to transform the look of your garden, balcony or driveway during the Christmas season, one way that you can do this is through outdoor Christmas lights. Powering them, however, can prove a bit of a challenge.

The good thing is that you can opt for a portable power station, use standalone solar lights, or even plug them into an outdoor power outlet. The right choice for you will depend on which option is most convenient.

Let's take a deeper look into how you can power your outdoor Christmas lights.

How Can You Power Outdoor Christmas Lights?

Existing Outdoor Outlet

Depending on where you need to place your display, one practical option is an existing power outlet. Use lights and any extension leads rated for outdoor use. Always ensure that you follow the instructions of the manufacturer.

If you find that you need an extension lead, ensure that you pick one rated for outdoor use. Also don’t route it across a driveway, walkway, windows, or doors where it can get damaged.

Battery-Operated Lights

If you don’t have an outdoor outlet, consider battery-powered Christmas lights. Be sure to check the manufacturer’s battery type, instructions, and operating time.

The rechargeable variety can spare you the hassle of replacements, while disposable batteries are a good choice if you plan on running the lights for a short time.

Standalone Solar Christmas Lights

The standalone solar Christmas lights have a rechargeable battery, solar panel, controller, and LED lights in one unit. These are an excellent choice for pathways, gardens, and other areas where low illumination is sufficient.

Of course, the performance of the standalone solar Christmas lights will boil down to the amount of sunlight received as well as the battery capacity.

Portable Power Station

If you don't have an outdoor power outlet, you can choose a portable power station for AC power. Find out the wattage of every light or decoration, add the total, and then use this information to choose a station that has enough output and usable capacity.

The BLUETTI Elite 30 V2, for instance, provides 288Wh of capacity and 600W of output. The BLUETTI Elite 100 V2 offers 1024 Wh and 1800W of output.

How Many Watts Do Outdoor Christmas Lights Use?

There really isn't a single wattage for outdoor Christmas lights, and a short LED string may only use just a few watts, while the longer strings, inflatables, projectors, and sets can use up significantly more.

The best figure to go with is the manufacturer's documentation on rated input.

For example, consider a display with three LED strings rated at 8W each. The lighting load is:

8W + 8W + 8W = 24W

If you add in a 20W decorative light, it becomes:

24W + 20W = 44W

You will use the 44W figure to estimate the power needed from the portable power station or a battery. Ensure that you check whether the low-voltage Christmas light also has a controller, as this can have different input requirements.

Also don’t assume that the Christmas light is weatherproof. Always check that the lights, as well as the associated equipment, are designed for outdoor use.

How to Calculate Nightly Energy Use?

After finding out the total wattage, calculate how much energy the display needs each night.

Total watts × operating hours = nightly watt-hours (Wh)

For example, imagine three LED strings each rated at 8W:

3 × 8W = 24W

If they run for six hours each evening:

24W × 6 hours = 144Wh

Now consider another 20W decorative light:

44W × 6 hours = 264Wh

The total 264Wh refers to the estimated energy that is consumed by all the lights and the load. Be sure not to treat the figure as the exact battery capacity you need. Note conversion losses, the inverter, usable battery capacity, as well as the reserve, to provide you with sufficient operating margin.

How Big a Battery Do You Need for Christmas Lights?

To get the right battery, you’ll need to understand the nightly energy needs rather than how many light strings you have. If your lights require 264Wh each night, a 64Wh battery is too small even before accounting for system losses. The battery must provide enough usable energy to cover the nightly load, conversion losses and operating reserve.

The more practical approach is to pick a battery that has greater usable capacity than the nightly energy demands. For instance, with a nightly energy requirement of 264Wh, you would need to get a battery capacity that is substantially higher than this figure.

For example, assuming 80% of nominal battery capacity is available to the lights after system losses, 264Wh ÷ 0.8 = 330Wh of nominal capacity, before adding any operating reserve. The 80% figure is an illustrative assumption, not a measured efficiency for either BLUETTI model mentioned here.

You will also need to consider the output ratings. Your battery may have sufficient Wh capacity but still be less ideal if the equipment surpasses its AC output rating. The BLUETTI Elite 30 V2, with its 288Wh capacity and 600W output, can suit lower-energy displays, but its nominal capacity alone does not establish that it can cover the 264Wh nightly example after system losses. But for a larger display, you may need the BLUETTI Elite 100 V2 for its 1800W of output and 1024 Wh capacity.

Can Solar Recharge the Setup During the Day?

A compatible solar panel can recharge a portable power station during the day, allowing you to use the stored energy for your Christmas lights at night. This is a completely different setup from standalone Christmas lights, which feature their own solar panel, controller, and LED lights all in one unit.

Solar charging can reduce the need to carry the portable power station back to a mains socket each morning. However, it's important to note that the rated solar panel wattage doesn't mean that this is the power it will deliver every day, as cloud cover, weather conditions, shading, and temperature all have a part to play in the panel's efficiency.

BLUETTI's solar generator kits combine compatible battery storage and charging equipment, while its portable solar panels provide a separate charging option. The panel and power station must be compatible, and the station's solar-input limits should not be exceeded.

If you plan on using it every season, such an approach offers more flexibility compared to trying to make a small standalone solar light run a high-demand display. The power equipment still requires positioning with regard to the operating instructions and the environment.

Outdoor Electrical and Weather Safety

Ensure that you choose Christmas lights and associated equipment that are rated for outdoor use. Check out the IP ratings as well as manufacturer instructions and ensure that the connections are kept safe from moisture. Also check the cables before use.

Outdoor-Rated Leads, RCD Protection, and Weatherproof Connections

Whenever you want to connect the outdoor Christmas lights to a mains outlet, ensure that the extension lead you use is rated for outdoor use and ideal for the load. Never run the lead through windows and doors or across walkways and driveways as they could easily cause damage or a hazard. Unwind the extension lead fully as this prevents the risk of overheating.

Another important part of outdoor electrical safety is the RCD or safety switch, and the Australian electrical safety guidelines recommend testing the safety switch and even having a portable safety switch in case the outlet isn't protected. Turn off Christmas lights before going to bed or leaving home, and switch off the power before adjusting or replacing them.

Connections exposed to the weather should be protected from water ingress, and every component must be suitable for its environment. Some outdoor Christmas-light systems have transformers that must remain indoors, so check the manufacturer's instructions rather than assuming the entire system can be exposed to rain.

Example Setups for Small, Medium, and Larger Displays

Small display: If you are running only a few LED strings as well as a pathway decoration, you can get by with just standalone solar lights or a battery. Assuming that the lights total 20W and run for 5 hours, you will have a 100Wh nightly power requirement.

Medium display: For someone with several LED lights and strings that total around 50W, and running these for 6 hours, the energy requirement goes up to 300Wh without accounting for battery system losses. In such an instance, a portable power station can work well, especially where there isn't any outlet outside. The BLUETTI portable power station range has both compact and high-capacity options.

Larger display: For a display that has multiple strings and other equipment like projectors and inflatables, it is ideal to size these using the actual rating for each device. Getting a high-capacity system such as the BLUETTI Elite 100 V2 can provide a steady 1800 W of output with a 1024Wh capacity.