Trolling motor batteries, while generally reliable, can sometimes experience bizarre failures that leave even seasoned anglers scratching their heads. Here are some of the weirdest Trolling Motor Battery fails and, more importantly, how to avoid them:

1. The “Phantom Drain” Caused by Stray Wires:

• The Fail: A seemingly healthy battery mysteriously drains overnight, even when disconnected. The culprit? A single, stray, uninsulated wire touching the boat’s hull or a damp surface, creating a slow but steady current leak.
• How to Avoid:
  • Thoroughly inspect all wiring for damage or loose connections.
  • Use marine-grade wiring and connectors.
  • Ensure all connections are properly insulated.  
  • Install a master disconnect switch and use it when the boat is not in use.

2. The “Exploding Battery” Due to Incorrect Charging:

• The Fail: A lead-acid battery explodes during charging, sending shrapnel and acid flying. This usually happens when a non-smart charger overcharges a battery, causing excessive gas buildup. Or when a lead acid charger is used on a LiFePO4 battery.
• How to Avoid:
  • Use a smart charger designed for your battery type.
  • Follow the manufacturer’s charging instructions.
  • Ensure proper ventilation during charging, especially for lead-acid batteries.  
  • Never use a lead acid charger on a LiFePO4 battery.  
  • Never leave a battery unattended while charging.

3. The “Frozen Solid” Battery in Summer:

• The Fail: A flooded lead-acid battery freezes and cracks, even in warm weather. This occurs when the water level is too high, and the battery is overcharged, causing the electrolyte to become diluted.
• How to Avoid:
  • Maintain proper water levels in flooded lead-acid batteries.  
  • Use distilled water for refilling.
  • Avoid overcharging.

4. The “Melting Battery” Caused by Loose Connections:

• The Fail: Battery terminals or wiring melt, emitting smoke and a burning smell. This is typically caused by loose connections, which create resistance and generate excessive heat.
• How to Avoid:
  • Regularly check and tighten battery connections.
  • Use high-quality connectors.
  • Ensure proper wire gauge for your trolling motor system.

5. The “Sudden Death” Caused by Vibration Damage:

• The Fail: A seemingly healthy battery suddenly stops working. This can happen when constant vibration from rough water or trailer transport damages the internal plates or connections.
• How to Avoid:
  • Securely mount your battery to prevent excessive movement.
  • Use battery tie-downs or clamps.
  • Consider using vibration-dampening materials.
  • Inspect your batteries regularly.

6. The “BMS Lockout” of a LiFePO4 Battery:

• The Fail: A lithium battery suddenly stops working, even when showing a full charge. This is usually caused by the battery management system (BMS) shutting down due to over-discharge, over-charge, or extreme temperature.
• How to Avoid:
  • Use a battery monitor to track voltage and state of charge.
  • Follow the manufacturer’s recommendations for charging and usage.
  • Ensure adequate ventilation to prevent overheating.
  • Purchase quality LiFePO4 batteries with a good BMS system.

7. “Critter Corrosion”

• The Fail: Wires and terminals are eaten away by rodents or other small animals. This can cause shorts, drains, and complete system failures.
• How to Avoid:
  • Store your boat in a clean area, free of food scraps.
  • Use wire coverings and rodent repellent.
  • Inspect wiring regularly.

Key Takeaways:

• Regular maintenance is essential for preventing weird battery fails.
• Pay attention to wiring, connections, and charging practices.
• Use high-quality components and follow the manufacturer’s instructions.
• When in doubt, consult a qualified marine electrician.
• LiFePO4 batteries require an extra level of awareness of their specific needs