Bosch cordless vacuum will not charge, charger LED blinks error pattern, vacuum display shows E05 when battery inserted

Safety first: Remove the battery from the vacuum and place it on a non-flammable surface away from direct sunlight or heat sources.

• Allow to cool: If the battery feels warm or hot, let it cool at room temperature for at least 30–60 minutes before attempting to charge again.
• Inspect environment: Ensure the charger is used in a cool, dry area (typically 5–35°C). Avoid charging in hot garages or near radiators.
• Check charger: Inspect the Bosch charger for damage, burn marks, or loose connections. Try a different wall outlet. If available, test with another compatible Bosch charger.
• Test another battery: If you have a second Bosch battery, try charging it on the same charger. If only one battery triggers E05, that pack’s internal sensor is likely faulty.
• Do not open battery: If E05 persists with a cooled battery, replace the battery pack. Internal temperature sensor faults are not user-repairable and opening the pack is dangerous.