Home Charging Fault in a First-Floor Flat
A customer who bought a 48 V, 2.5 kWh removable-battery e-scooter charges it at a public charging point without trouble, but at home the charger LED flickers and the scooter often refuses to charge. He lives on the first floor and runs a 10 m extension reel from a 15 A three-pin socket in the kitchen to the charger on the balcony. The plug pins are discoloured, the extension reel feels warm, and the house MCB sometimes trips when the refrigerator starts. He has replaced the 6 A MCB with a 16 A one once, and it still trips. He brings the scooter and charger to the workshop and asks you to “repair the charger or sell a bigger fuse.” The charger is an aftermarket 54.6 V, 8 A unit with a two-pin IEC inlet and no visible BIS mark. The workshop has a dedicated 16 A EV test socket with RCD protection and a known-good charger of the same voltage. The customer is worried about cost and says the builder’s electrician “does not understand EVs.”
1. How would you separate a charger fault from a home installation fault, using the workshop’s test socket and known-good charger? Give a safe sequence.
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First inspect the customer’s plug, socket and extension reel for heat, discoloration, loose pins and cracked insulation; do not touch live parts. At the workshop, use the dedicated 16 A RCD-protected EV socket. Measure the supply voltage, then connect the customer’s charger with no vehicle and check its standby output; then charge a known-good scooter or load. Record input voltage, current, output voltage, and whether the LED remains steady. If the charger works correctly at the workshop, the fault is likely in the home supply, extension lead or socket. Test the known-good charger on the customer’s scooter to rule out the vehicle inlet. Isolate before changing connections. Do not use the customer’s extension reel as a test lead. The discoloured plug and warm reel are signs of a poor connection/high resistance, not proof of a charger fault. Only a qualified electrician should test the fixed wiring.
2. The customer has already replaced a 6 A MCB with a 16 A unit and asks you to fit a bigger fuse. Explain the danger and what a correct installation needs.
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The MCB protects the cable, not the appliance. Fitting a larger MCB on the same undersized cable or shared circuit allows the cable to overheat before the breaker trips, which can cause a fire; it also does not fix a loose socket, a damaged extension lead or a high-resistance connection. A proper EV charging point needs a dedicated circuit sized by an electrician for continuous load, correct cable cross-section and voltage drop, an RCD of the type required by the charger/OEM (often Type A plus DC 6 mA detection or Type B), a good earth, an IP-rated socket or hard-wired connection, and isolation/protection coordinated with the house board. The charger must be suitable for the vehicle and certified. I would not increase the fuse or modify the customer’s wiring; I would give him a written referral to a licensed electrician and a checklist of what to ask for.
3. How would you document the case and advise the customer without losing his trust?
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Open a job card with the scooter VIN, charger make/model/serial, measured voltages and currents, test results at the workshop, photos of the discoloured plug and reel, and a clear statement that the scooter/charger worked on the test socket. Separate “vehicle/charger findings” from “building wiring-not tested by us.” Give the customer a short written explanation: the charger is probably not the cause; the home circuit and extension lead need an electrician; do not use the extension reel; do not fit a bigger MCB. Provide a quote for a replacement plug/lead if damaged and for a charger check, and a referral list. Ask him to sign that he received the advice, especially if he declines. Follow up after the electrician’s visit and record the outcome. This protects him, protects the workshop, and turns a refusal into a trust-building service.