What are Battery Assisted Passive (BAP) RFID Tags?

Battery Assisted Passive RFID Tags are passive RFID tags with an embedded battery. When a BAP tag receives an RF signal from an RFID reader, it turns on the embedded battery which in turn powers the RFID Tag IC, sensors or actuators in the tag. The RFID tag information is then sent to the RFID reader using backscatter. So its operation principle is similar to passive tags, i.e. its battery only turns on once the reader sends it an RF signal.

Active tags on the other hand, do not need to receive a signal from the RFID reader to turn on, they are always on and send the required tag information to the reader from time to time. Active tags also have radio transmitter other than the RFID Tag IC, battery and antenna. BAP tags only have an RFID tag IC and antenna with a battery.

Since BAP RFID tags are battery powered they have a range greater than passive tags (but less than active tags). These tags can also have integrated sensors or actuators which can be used to send other information like temperature, humidity etc. along with the basic tag information. The battery in BAP tags are usually not replaceable, and once it dies out these tags need to be replaced.

Battery Assisted RFID Tags are usually more expensive than passive tags and less expensive than active tags.