Replace Battery — Controller Backup Battery Low
The SULLAIR-REPLACE-BATTERY (Sullair WS Controller) diesel fault code means: Replace Battery — Controller Backup Battery Low. This is a low severity code.
- DIY difficulty
- moderate
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Common Symptoms
- WS display shows Replace Battery warning; machine runs normally
Probable Causes (Ranked by Likelihood)
- Controller I/O backup battery low (maintains clock and memory records) High
Frequently Asked Questions
What battery does the WS Controller take?
Type BR2330, located on the I/O module circuit board. The manual's procedure requires a full lockout/tagout before opening the enclosure.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
The WS Controller is fitted to Sullair STATIONARY electric shop compressors. Portable towable Sullair units (185-class and similar) use different engine-driven controls and a different fault system — this page does not apply to them.
Replace with a type BR2330 battery. Factory procedure: press STOP, disconnect and lock out power, open the controller enclosure, remove the six screws on the I/O Control Module cover, replace the battery near the end of the I/O board, refit and restart.
Do not ignore it indefinitely: with a dead battery, time-of-day records fail and recent settings/records can be lost on a power cycle.
Per the factory manual: after resolving a fault condition, press the STOP pad to clear the FAULTED state. If the problem persists after the recommended checks, consult your Sullair distributor or factory service.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- Sullair WS Controller User Interface Manual, P/N 02250165-411 (Table 5-1 Troubleshooting Guide)distributor-hosted copy of the official Sullair manualdistributor-hosted copy of an official Sullair factory manual
Commonly Affected Vehicles
- Sullair STATIONARY electric rotary-screw compressors with the WS Controller (including VSD packages)
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