A fully charged battery lasts on average 4-8 hours. Also the battery life depends on the brightness setting. With a low light, the lamp can run for a full 8 hours, with a medium light - 6 hours, with a very bright light - 3-4 hours.
Also, when buying a wireless lamp, pay attention to the type of battery, which can be disposable or rechargeable. Buying a cordless table lamp with a very large battery capacity is always more profitable. Everyone needs a lighting fixture that will work for long hours. The more wattage, the more convenient it is.
The third important parameter is the lighting settings. Look for lights where you can adjust the temperature of the light from cool to warm depending on whether you're reading in bed or solving math problems with your child at your desk. Also important is the diameter of brightness, which allows you to diffuse the light over a large area or focus it in one spot. Lux is also important, which shows the ability of the device to illuminate a specific area.