PLC Battery Low

PLC backup battery voltage is low. Risk of losing program and data if power is removed.

Probable Causes (ranked)

• Battery has reached end of life — typically 3-5 year replacement cycle
• Battery not making good contact in holder — corrosion on terminals
• Frequent or extended power outages draining battery faster than normal
• Wrong battery type installed during last replacement

Fix Steps

1. 1 Replace battery with PLC powered ON — this preserves program during swap
2. 2 Use correct battery type per PLC manual — do NOT substitute different chemistry
3. 3 Clean battery holder contacts before inserting new battery
4. 4 Verify program is backed up to memory card or laptop before battery swap as safety measure
5. 5 Record battery replacement date on PLC enclosure door for tracking

Suggested Replacement Parts

Parts matched to fault category: Plc Battery

Prices are estimates. Verify part numbers match your equipment before ordering.

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