An RFID tag is an active tag when it is equipped with a battery that can be used as a partial or complete source of power for the tag’s circuitry and antenna. Some active RFID tags contain replaceable batteries for years of use; others are sealed unites.

The major advantages of active RFID tags are: (1) It can be read at distances of one hundred feet or more, greatly improving the utility of the device; (2) It may have other sensors that can use electricity for power.

The problems and disadvantages of active RFID tags are: (1) The tag cannot function without battery power, which limits the lifetime of the tag; (2) The tag is typically more expensive, often costing $20 or more for each; (3) The tag is physically larger, which may limit applications; (4) Battery outages in an active tag can result in expensive misreads.