E08
Festool Undervoltage / Battery Protection Triggered Under Load

Vacuum stops with E08 after a short run time, battery still shows charge on its LEDs

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Battery pack with high internal resistance, Poor contact at battery terminals, Defective battery cell group, Faulty undervoltage detection circuit on control PCB

How to Fix / Troubleshooting

Safety first: Remove the battery before inspecting contacts.

  • 1. Test battery in another tool: Use the same Festool battery in another cordless tool under load. If the other tool also cuts out quickly, the battery is likely weak and should be replaced.
  • 2. Clean and inspect contacts: Clean the battery and vacuum terminals with a dry cloth. Ensure the battery locks firmly into place without excessive play.
  • 3. Try a different battery: Install a fully charged, known-good Festool battery. If E08 disappears, the original battery is at fault.
  • 4. Check for heat: If the battery becomes unusually hot during short use, discontinue use; the pack may be failing internally.
  • 5. Control board check: If multiple good batteries all trigger E08, the undervoltage sensing circuit on the control electronics may be defective. This requires replacement of the control electronics module by a service center.
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Repair Difficulty

Medium 3/5

Required Part

Battery Pack
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