Make sure the power inverter has enough wattage output to accommodate your Christmas lights. Since Christmas lights are small, it's often easy to forget that they can draw a lot of power; according to ChristmasLightsEtc.com, an online holiday lights dealer, most standard Christmas light bulbs draw five or 10 watts each, depending on the exact light model. A string of 25 Christmas lights rated at seven watts each will draw 175 watts of power. To cut back on light wattage, consider using LED lights. ChristmasLightsEtc.com explains that 25 LED Christmas lights only draw 2.4 watts for the entire set.
Do not install a power inverter on your golf cart while the cart's engine is running. Always work on the cart with the engine safely turned off.