A flashing red and green light on a battery tender typically indicates an issue preventing the battery from charging correctly. According to the provided reference, it usually points to one of the following problems:
- Reverse polarity connection: The charger cables are connected to the battery with reversed polarity (positive to negative, and negative to positive).
- Sulfated battery: The battery plates have accumulated a layer of lead sulfate, hindering the charging process.
- Corroded battery terminal: Corrosion on the battery terminals is creating high resistance, preventing proper connection.
- High resistance output connection: An issue anywhere in the connection between the tender and the battery is causing high resistance. This could include loose connections, damaged wiring, or corrosion on terminals.
Troubleshooting Steps
Here's a breakdown of how to troubleshoot each potential cause:
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Check the Polarity:
- Visually inspect the connections. Ensure the positive (+) cable from the tender is connected to the positive (+) terminal on the battery, and the negative (-) cable is connected to the negative (-) terminal.
- Correct any reversed connections immediately.
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Inspect for Corrosion:
- Examine the battery terminals and cable connectors for signs of corrosion (a white or bluish-green buildup).
- Clean corroded terminals with a wire brush or a specialized battery terminal cleaner. Apply a corrosion protectant afterward.
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Evaluate Battery Condition (Sulfation):
- If you suspect sulfation, you can try a desulfation mode if your battery tender has one. Some advanced battery tenders have this feature.
- If your tender doesn't have a desulfation mode or the desulfation doesn't work, the battery might be beyond recovery and need replacement. Consulting a battery professional is recommended.
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Examine Wiring and Connections:
- Check the wiring between the battery tender and the battery for any damage, breaks, or loose connections.
- Ensure all connections are secure and free from dirt or debris.
Important Considerations
- Safety First: Always disconnect the battery tender from the power source before inspecting or cleaning any connections.
- Consult the Manual: Refer to the specific manual for your battery tender model. The manual might provide more specific troubleshooting steps or error code interpretations.
- Professional Assistance: If you're uncomfortable working with batteries or electrical systems, seek help from a qualified technician.
- Battery Age: An old battery might fail to charge correctly, regardless of the battery tender's condition.
