It's a small, cheap component, but ignoring it causes one of the most frustrating stoppages on an ABB robot: the SMB battery. Understanding what it does and when to change it saves you a recalibration and hours of downtime.
What the SMB battery is and what it does
SMB stands for Serial Measurement Board, the board that reads axis position. Its battery keeps the revolution counters when the robot is unpowered. Thanks to it, when you power the robot back on it remembers where each axis is and can start without recalibration.
What happens when it runs out
If the battery runs out with the robot off, the revolution counters are lost and a revolution counter not updated error appears. Then you have to update the counters (and, in some cases, recalibrate), which means a technician and downtime. In other words: a fault in a component worth a few euros ends up costing a full intervention.
Warning signs
- A low battery message on the FlexPendant.
- Recurring warnings after long power cuts.
- Old robots (S4, IRC5) with no record of the last replacement.
How often to change them and how
As a reference, every 1 to 3 years depending on model and usage, or as soon as the warning appears. Two key best practices:
- Replace them with the robot powered on (or following the ABB procedure) so as not to lose axis position.
- Record the replacement date to anticipate the next one and not depend on the warning.
This task fits perfectly into the ABB preventive maintenance plan, along with lubrication and axis inspection.
Frequently asked questions
What is the SMB battery for?
It keeps the axis revolution counters with the robot off, so it remembers its position and no recalibration is needed.
What happens if it runs out?
The robot loses the counters and gives a revolution error; they must be updated and sometimes recalibrated, with downtime included.
How often are they changed?
Every 1 to 3 years or when the warning appears, and preferably with the robot powered on so as not to lose position.