What causes Haas alarm 1?

Battery lifespan expired after 5-7 years of typical service life on the MOCON board. Poor battery contact or corroded battery holder terminals on the MOCON absolute encoder battery socket. Battery drain caused by extended periods of machine being unpowered for months at a time. Faulty MOCON board circuitry drawing excessive current from the battery circuit. Incorrect battery type installed during previous service, such as non-lithium or lower capacity cell.

How do I fix Haas alarm 1?

1. Step 1: Check battery voltage at the MOCON board using a multimeter - should read 3.2 to 3.6 VDC for healthy lithium cell 2. Step 2: Inspect battery holder for corrosion, bent contacts, or poor seating of the battery in the socket 3. Step 3: Replace battery with Haas part number or equivalent CR2032 lithium cell, ensuring proper polarity during installation 4. Step 4: Clear the alarm and perform a complete home cycle on all axes to re-establish machine reference position 5. Step 5: Monitor battery voltage in Diagnostics page under the MOCON section for 24-48 hours to verify stable voltage above 3.2 VDC 6. Step 6: If alarm returns immediately after battery replacement, suspect faulty MOCON board and prepare to replace the board with updated machine parameters

Haas codes

axismd.ai

Haas Controller

Power Supply · Basic · 15-30 minutes

Alarm 1

Haas Alarm 1 - Encoder Battery Low

Haas Alarm 1 (Low Battery) occurs when the backup battery voltage drops below the minimum threshold required to maintain NVRAM memory and real-time clock functions. This alarm typically indicates the internal lithium battery needs replacement or has failed completely.

HaasPower SupplyBasic15-30 minutes

1

Haas Alarm 1 - Encoder Battery Low

Low Battery

This alarm indicates the absolute encoder battery voltage on the MOCON board has dropped below acceptable levels, typically below 3.0 VDC. The battery maintains machine position data when the control is powered off, and low voltage will result in loss of home position reference. The machine will require a re-home cycle after the alarm is cleared, and continued operation without replacing the battery risks losing machine zero at every power cycle.

Root Cause Summary

Safety

Position data at risk
Replace within 24 hours

Causes and Fixes

1
Check Battery Voltage Display
Press CURRENT COMMANDS, then navigate to DIAGNOSTICS > BATTERY to view current battery voltage. Normal voltage should read 3.0V or higher.
Document the voltage reading for service records
2
Power Down and Replace Battery
Turn off main power and disconnect AC power. Remove control panel cover and locate the lithium battery (usually CR2032 or equivalent). Replace with identical battery type.
Always power down completely before battery replacement to prevent data corruption
3
Restore Parameters and Clear Alarm
Power up the control, reload machine parameters from backup, reset clock via SETTING 7 (TIME), and press RESET to clear alarm 1.
Always have current parameter backup before battery replacement

DIY Feasiblehigh confidence

Call a technician if:

·Control board replacement needed
·Repeated battery failures
·Parameter corruption persists after restoration

Prevention

Replace battery every 3-5 years preventively
Monitor battery voltage monthly via diagnostics
Maintain parameter backups
Keep spare battery in stock

Common Mistakes

Not powering down before battery replacement
Using wrong battery type
Forgetting to reload parameters after replacement
Not checking battery holder contact condition

Related Alarms

719 720 721

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.