Charger shows E05 and does not energize; no relay click is heard when starting a session.

Safety: Do not attempt to open or tap on the charger to free a stuck relay. High voltage components are inside.

• Power-cycle: Disconnect the J+ Booster from mains for 2–3 minutes, then reconnect and attempt a charge. Listen for a distinct click when charging should start.
• Check for overheating signs: Smell for burnt odor near the housing and look for discoloration or warping. If present, discontinue use immediately.
• Verify supply current rating: Ensure the J+ Booster is configured (if adjustable) to a current level supported by the circuit and outlet. Repeated overloads can damage the contactor.
• Try a lower current setting: If your J+ Booster model allows current selection, set it to the lowest level and test. Persistent E05 indicates internal relay issues.
• Professional service required: Replacement of the main contactor or main control board must be done by a qualified technician due to live parts and sealing requirements.