Buying a Used Dolphin from a Dealer - advice

[derbydan]

Hi,

If you were considering buying a used Dolphin (Comfort) from a BYD Dealer what things other than listed below would you want to ask and seek answers to:

1) That the car is the right one for you (after a test drive) and is mechanically sound.

2) The Battery State of Health is good. Would you want to personally check this ?

3) What would you consider an unacceptable level of battery degradation on a car less than 1 year old ?

4) What items would you be looking at in particular on the test drive? Obviously tyre wear. Paint work. Tracking of wheels (I'd test at low speed by letting go of the steering wheel and seeing if the car veers off straight).

5) What does the dealer need to have done to ensure the smooth handover eg (getting you set up with BYD so you can use the App asap), and charging the car sufficiently to get you home.

Many thanks

 

[Stuart Wright]

Other than your 5 questions above (this is a pretty comprehensive list):

Vehicle history and provenance

• Full service history, invoices, and any warranty work records.
• Accident or repair history, where repaired, and parts used.
• HPI or equivalent history check, outstanding finance, mileage verification.
• Previous usage pattern. Private, demo, fleet, taxi, rental.
• Number of rapid charge sessions vs AC charges if the dealer can evidence it (more DC = worse).

High voltage battery and charging

• Official battery health printout from BYD diagnostic tools, including SOH, cell voltage delta, and BMS version.
• Confirmation the traction battery warranty transfers to you, with exact expiry date and mileage limits.
• 12 V battery age and test result. Many EV issues are 12 V related.
• Evidence that all HV-related recalls or campaigns have been completed.
• Charge port condition, pin wear, latch operation, and charge door alignment.
• Included charging accessories. Type 2 cable, granny charger, V2L adapter if applicable.
• Perform a live charge test on AC at the dealership to confirm expected rate and that the car takes a charge cleanly.

Software, keys, and digital setup

• Car fully unbound from the previous owner in BYD systems.
• Dealer to bind the car to your BYD account at handover and verify the app connects.
• Head unit and vehicle firmware updated to the latest version, with release notes.
• All keys present and working, including key cards if supplied. Ask for a spare to be programmed if missing.

Recalls, campaigns, and consumables

• Written confirmation that all recalls and service campaigns are closed.
• Brake service on EV schedule. Check for disc corrosion and seized sliders. EV brakes are used less and can get rusty if you don't slam the anchors on every so often.
• Tyre date codes, brand matching, and remaining tread.
• Cabin filter and any coolant service items up to date per BYD schedule.

Equipment and spec verification

• Confirm Comfort trim features that matter to you. Heat pump, driver assists, wheels, charging hardware.
• Check every powered item. Windows, mirrors, locks, tailgate, seats, steering wheel controls, cameras, parking sensors, wireless charging pad, USB ports, infotainment functions, voice control, Bluetooth. Most important is that the screen rotates (kidding!).

On-ramp inspection before the test drive

• Underbody trays, jacking points, and sill seams for lift damage.
• Evidence of previous smart repairs or overspray around panels and rubbers.
• Windscreen condition and proof of ADAS camera calibration if it has been replaced.

Additional test drive checks

• Straight-line stability at various speeds, not just low speed.
• Steering feel, dead zone, and any clicks or clunks over bumps or while parking.
• Suspension noise on rough surfaces and speed humps.
• Brake feel and straight, vibration-free stops from urban and A-road speeds.
• Regen levels work correctly and no driveline shudder at high regen.
• HVAC performance. Cabin heats and cools quickly, heat pump quietness, demist speed.
• Infotainment responsiveness, CarPlay or Android Auto stability, and speaker buzz or rattles.
• Wind noise around mirrors and doors at 60 to 70 mph.
• One full power acceleration to check for abnormal whine or vibration.

Documentation and handover

• Exact remaining manufacturer warranties listed on the invoice. Vehicle, battery, drive unit, paint, corrosion.
• Second key, locking wheel nut key, parcel shelf, mats, tow eye, jack or inflation kit, and any original accessories.
• Printed checklist of pre-delivery inspections, software versions, and recall closure.
• Agreed return or exchange policy and any dealer warranty terms in writing.
• Sufficient charge at handover and a nearby charger pinned in the nav for your route home.

Nice to have

• Short DC fast charge test to confirm the car reaches an expected peak and holds a stable curve.
• Wheel alignment report if tyres show any edge wear.
• Photos or video of the car on a four-post lift to document the underbody condition.