Buyer's Guide to Alarm Clocks and Clock Radios

While an alarm clock is generally considered to be a simple, basic purchase, a number of features and characteristics should be looked for when purchasing one.

Battery Back-Up: Most alarms have this feature, although it is not included on some vintage and portable units. A back-up battery not only prevents your time settings from being lost during power outages but reduces wear on the time setting buttons, which are often the first part of an alarm clock to wear out. Almost all alarm clocks use square 9V batteries for back-up, although a few use "AAA" or other battery types. If you purchase a used alarm clock, especially if it is entirely battery operated (portable), you may want to check for any corrosion in the battery compartment.

Analog/Digital: Digital alarm clocks and clock radios have some advantages, in that they can be seen at night (except for some LCD portables) and allow more precise setting of the alarm time. Analog units, on the other hand, are less likely to fail because they don't use buttons to set the time. However, make sure an analog clock doesn't tick or hum too loudly before purchasing it.

Snooze Button: The "Snooze" button, sometimes marked as "Drowse", allows you to turn the alarm off temporarily after it has sounded. A few models let you select the number of minutes until it sounds again. Some vintage or travel clock radios don't have this feature. Analog clocks with a "Snooze" button are available but less common.

Dual Wake Times: If you desire to set the alarm for two different times during each day or week, this is a good feature to look for. Clocks with this feature are usually more expensive, but this prevents mistakes in setting the alarm time, is more convenient, and makes the setting buttons less likely to fail from overuse.

Sleep Timer: Many clock radios offer a sleep timer which lets you turn the radio on for a certain amount of time and have it automatically turn itself off after the time has elapsed. The amount of time can usually be adjusted, although increments vary.