The purpose of the Serial Measurement Board (SMB) is to track the location of the various axes on the robot by recording the encoder value attached to each motor on each axis. If the robot looses power the battery attached to the SMB will recall the last known position of the motors when power was lost. Allowing the robot to wake up knowing the location of each axis and continue where it last left off . The SMB and battery can be found in the base of the robot. These batteries need to be changed periodically. This is usually done during preventative maintenance of the robot although not necessarily every time.

Why we need to ask for the part number: and why the robot type and serial number isn’t enough?
the answer is simple: it’s all about versioning.
Manufacturers release different versions of the same robot model over time, and each version may have unique features or improvements that require different spare parts. These changes may be driven by factors such as improvements in the design, advances in technology or certain components not being available anymore.
Even with the same robot type you find different versions due to parts replaced over the years of operation etc.
To minimise your robot downtime, it’s important to identify the correct part number to order.
Photo below,
3 different SMB’s & batteries from 3 identical robots

The battery on the left is 4944026-4 with 6 cells , the middle is 3HAC16831-1 with 3 cells and the one on the right is 3HAC044075-001 with 2 cells