ABB Robot SMB Battery Replacement & Revolution Counter Update
Why an ABB robot loses its position after power-off
Switch off the mains to an IRC5 controller, come back later, and you may find the axis positions showing in red on the FlexPendant, with the robot refusing to run a program. The arm has not moved. What it has lost is the count of how many full turns each axis has made — the revolution counters — and without that count the controller cannot work out where the arm actually is.
That count is kept alive by a small lithium cell on the SMB, the Serial Measurement Board. While the controller has mains power the cell does very little; cut the mains and it becomes the only thing still holding the counters. Which is why it has to be replaced before it runs down. Once it is dead, every mains-off / mains-on cycle loses the counters, and the line waits while someone jogs six axes back to their reference marks.
So this guide is really about two jobs. Replacing the battery in time — a consumable swap, done with the controller still powered on, that skips the update entirely. And updating the revolution counters when you are already too late.
Two things are worth getting straight first, because both catch people out. A new battery does not bring lost counters back: if they are already gone, fitting a fresh cell changes nothing until you run the update. And strictly, the battery holds the revolution count, not the whole "position" — the exact position comes from the resolver reading plus the revolution count, while the calibration values sit in the SMB and survive power-off. Put plainly, the cell is the keep-alive for the robot's zero. Replace it in time and nothing moves. Let it die and you re-teach the zero.
If 38213 or 38200 is already on your pendant, the cell is telling you it is on its way out, and you are still inside the window where a powered-on swap keeps your counters. Send us the robot type and serial number and we will confirm the correct cell for your IRB before you power anything down — remotely, no site visit.
What the battery is actually holding on to
ABB puts it precisely in the IRC5 operating manual (3HAC050941, §4.6.9): the exact position of the robot is determined using the position of the resolvers and counters that count the number of resolver revolutions — these are the revolution counters.
In practice, position data is three separate things, and only one of them depends on the battery:
| What it is | Where it lives | Needs the battery? |
|---|---|---|
| Resolver reading — the angle inside one turn | Measured live by the resolver | No |
| Revolution counter — how many whole turns | SMB, kept alive by the battery | Yes |
| Calibration values — the fine calibration | SMB serial memory | No — survives power-off |
That split explains both the failure and the fix. Swap a healthy cell with the controller still powered and you lose nothing: the counters stay, and no calibration work is needed. Let the cell die — or power the robot down on an already-dead cell — and you lose the middle row only. Which is why the recovery is a revolution counter update and not a full recalibration: the fine calibration is still sitting in the SMB.
The warnings you will see on the FlexPendant
38213, Battery charge low is the one you want to catch. ABB's troubleshooting manual is blunt about it: replace the battery at a suitable opportunity, and do not turn the controller off until you have. (The Chinese revision of the same document phrases the urgency differently — the cell will be depleted within about two months of the message first appearing. Treat that as a planning window, not a promise.) Caught here, the whole job is one part and a few minutes, and the counters never move.
38200, Battery backup lost means the backup is already gone — the cell is discharged or disconnected. ABB notes that on some models the battery is fed through a jumper in the robot's signal cable, so unplugging that cable cuts battery power too. The event log keeps repeating the warning, and the manual states the consequence plainly: the robot will lose the revolution counter data. The way out is to fit a charged cell, then update the counters.
Two rarer codes belong to the same family. 38214, Battery failure appears when a Bat_shutdown attempt did not take — that routine is covered in the last section; retry the shutdown, and if it keeps failing, the SMB board itself needs replacing. 38215, Battery supervision failure is handled by repeating the counter update for the joints on that SMB — and again, if it persists, the board is the next suspect.
You may also see 20032, revolution counter not updated, after the counters are lost, and 50057, joint not synchronized, at startup until the update is done. Both point to the same recovery, covered below.
Read the event log, then:
- 38213 → keep the controller ON and swap the cell soon → counters retained, no update needed.
- 38200 → fit a charged cell, then update the revolution counters → re-check program positions.
- No battery alarms → check 38103 / 50296 / drive faults — not a battery problem.
Replacing the battery without losing your zero
Safety first, because both the cabinet and the arm can bite. De-energize and lock out where your site requires it. If you power the controller down, wait for the DC-bus capacitors to discharge before touching anything inside. Released brakes can let an axis drop, so control the arm. And treat the cell like any lithium pack: no short circuit, mind the polarity, recycle the old one.
On most IRB models the SMB and its cell live in the robot base; a few configurations differ, so check your product manual if the layout looks unfamiliar. The swap itself:
- Read the battery status on the FlexPendant and note which unit is affected.
- Keep the controller powered on if the old cell is still alive — that is what keeps the counters.
- Open the SMB compartment, release the retaining clip and unplug the connector.
- Fit the new cell — 3HAC043118-001 is the standard IRC5 SMB backup cell. Confirm it against your IRB model; send us the serial number and we will check.
- Reconnect, clip in, and confirm the pendant shows a healthy battery status.
- If the counters were retained, you are done — no update needed. If the cell was already dead, or an SMB or a motor has been replaced, read on.
If you would rather have a second pair of eyes before you order anything, send us the event log extract and your robot type. We will read it remotely and tell you whether the battery is really the whole story — sometimes it is not, and we would rather tell you that than sell you a cell you do not need.
Updating the revolution counters
First see what the controller itself says. On the ABB menu, tap Calibration; each mechanical unit shows one of three states:
| Status on the pendant | What it means |
|---|---|
| Calibrated | Nothing to do |
| Rev. counter update needed | Run the update below |
| Not calibrated | Full calibration by a qualified technician — a different job |
For the update, the robot goes in Manual, motors on, enabling device held — and every axis must be jogged exactly onto its calibration reference mark, the scribe lines on each joint. Doing this away from the marks stores the wrong position. Then:
- On the ABB menu, tap Calibration.
- Tap the mechanical unit, then Rev. Counters.
- Tap Update Revolution Counters.
- Read the warning — updating may change programmed positions — and tap Yes.
- Tick the axes to update, or Select all, then Update.
- Confirm the second, cannot-be-undone warning with Update.
- Wait for sampling to finish and tap OK.
Verify with a power cycle: positions should show in black, and no 50057 should appear at startup. If red text remains, an axis was off its mark — re-jog it and repeat. Some IRB product manuals also describe the CalHall routine for a more precise update; the path above is the standard rough method, and your product manual gives the model-specific calibration positions and scales.
One boundary worth respecting, in ABB's own words: "Do not attempt to perform the fine calibration procedure without the proper training and tools." A counter update is a rough calibration. Fine calibration is a different job.
When the battery is not the problem
Red positions plus 38213 or 38200 is the battery's signature. Two alarms in the same neighbourhood are not. 38103, lost communication with the SMB, is a cabling, shielding or board problem — work the official sequence from connectors, to shield, to interference, to boards. 50296, manipulator memory data difference, shows up after an SMB or controller swap, or a serial-number mismatch: verify the configuration data, and if a board from another robot has gone in, clear its memory before transferring data from the controller. And 38216 / 38217 mean the SMB functionality check expects a newer board generation, DSQC 633C/D or later.
The battery fixes one failure family. If the log says something else, swapping a cell will not help — send us the codes and we will tell you which family you are actually in.
Parts this guide touches, for reference:
| Part | ABB part no. | When it is the right part |
|---|---|---|
| SMB backup cell | 3HAC043118-001 | 38213 / 38200, low battery status, preventive swap |
| SMB board | DSQC 633 (C/D or later) | 38103 / 50296 after the checks above, 38215 persisting, 38216/38217 generation check |
| Brake release unit | 3HEA801009-002 (confirm per model) | Moving axes by hand to the reference marks |
| IRC5 system power supply | DSQC 661 | Controller will not boot, power faults — a different family |
Making this a non-event
A cell costs next to nothing next to an unplanned stop, so most maintenance teams treat it as a calendar item: glance at the battery status screen during PM, and replace the cell roughly every 12–18 months. Your IRB product manual has the interval for your model — follow it. Plan the swap into a planned stop, keep the controller on, and it never touches production.
There is also an official routine for one specific situation. If a robot is being shipped or stored for months, SMB units with a 2-pole battery contact have the Bat_shutdown service routine, which switches the battery backup off to save the cell. On 3-pole units do not use it — the drain is already negligible. Two things to know before you run it: jog the robot to its calibration position first, and expect the counters to be gone at the next power-up. The backup switches itself back on automatically, but the counters do not come back with it — you update them once, and the calibration values are still there.
FAQ
What happens if the SMB battery dies?
The revolution counters are lost the next time mains power goes off. Positions show in red, the robot refuses to start a program, and you update the counters before production resumes. The calibration values are not lost — so it is an update, not a recalibration.
Does a dead battery mean I lose the robot's calibration?
No. The fine calibration lives in the SMB serial memory and survives power-off. What dies with the cell is the revolution count, which is why a counter update — not a full calibration — puts you back.
How often should the battery be replaced?
A common guideline is every 12–18 months as preventive maintenance, or as soon as a low-charge warning appears. Your IRB product manual gives the interval for your model.
Can the battery be replaced while the robot is in production?
Plan it into a normal stop, with the controller still powered on — the powered-on part is what keeps the counters. Done that way, the job takes minutes and production is not affected.
What is alarm 20032?
"Revolution counter not updated" — the controller's reminder that the counters were lost and have not been updated yet. Run the update above and it clears.
Why do the axis positions show in red?
Red text means the stored counter value is gone and the pendant is showing the SMB fallback value. Until you update the counters, the robot will not run a program.
The robot was stored or shipped for months — why do the counters need updating now?
If Bat_shutdown was run on a 2-pole SMB to save the cell during transport, the counters were switched off with it. The backup re-enables itself at power-up, but the counters do not come back — one update and you are done, calibration values intact.
What is the difference between 38213 and 38200?
38213 is the early warning — the cell is running low, replace it, and do not power down first. 38200 means the backup is already lost: the counters are at risk or gone, and you will need the update after fitting a charged cell.
What information do you need to quote a battery?
Robot type and serial number are enough to start. RobotWare version — or just a photo of the system info screen — and the event log code help us confirm faster, but send the serial number first if that is all you have.
Can I ask a technical question without buying anything?
Yes — and that is usually the right first step. Send the code and your robot type and we will help you read it remotely. If the root cause is not the battery, we will tell you so rather than sell you a cell you do not need.
If you need a hand
Three situations, one route. If you have an alarm on screen — 38213, 38200, red positions — send the code plus your robot type and serial number, and we will confirm the right cell and quote it. If you are not sure the battery is the problem, send the event log and we will read it before you order anything. And if you are planning ahead, tell us your IRB models and your next planned stop, and we will help you line the cells up so the swap happens powered on. All of it remote — your engineers stay on site, we work alongside them.
Sources
- ABB, Operating manual – IRC5 with FlexPendant, 3HAC050941-001 Rev G — §4.6.9, §5.9.2, §10.1–10.2.
- ABB, Operating manual – Troubleshooting IRC5, 3HAC020738-001 Rev AA — event log 38200 / 38213 / 38214 / 38215 (p. 193), 20032, 38103, 50057, 50296.
- ABB, 故障排除手册（报警代码）, 3HAC020738-010 Rev L — Chinese revision of the same document.
- ABB, Safety instruction for battery, 3HAC043118-001 — cell handling.
- Your IRB product manual — model-specific calibration positions, scales and battery interval.
Independent technical content, not an official ABB document. ABB, IRC5, FlexPendant, IRB and RobotWare are trademarks of ABB. Follow your product manual and your site's safety rules: de-energize, lock out, wait for the DC bus to discharge, qualified personnel only.
