No, not the keyfobs. Though I’ve replaced them plenty. Or the 12V lead-acid, Tesla replaced that last year. No, the big one, 6 thousand cells of the 70kWh battery under the floor of my Model S.
The first symptom was one I’d seen early on in our ownership – so I knew it was serious, a grounding fault on the HV system. This can be any of the cabin heater, coolant heater, motors or battery itself. The car went into a limp mode with no regen braking and a 100kW power limit. Driveable, but not an excessive amount of power for a 2 tonne car.
11 November: Tesla took the car in, and we got a 5-year-old Model X 75D as a courtesy car. Sounds great but in reality it probably has the lowest range of any Tesla. In rain it’s easy to get under 2 miles per kWh, and the range then is only slightly better than our benchmark car, the awesome Hyundai Ioniq 28kWh. (BTW in 5 years it’s had no HV issues!) The doors are fun, but it’s just too big on many of Oxfordshire’s roads. In the UK this size car is really only practical on large roads and motorways. First world problems.
Tesla spent 3 days testing the HV systems, I guess the computer isn’t clever enough to isolate the fault very well, finally they opened the battery pack- to find water ingress. Some early cars have seen this due to the aircon draining it’s condensate water onto the fuse cover at the top of the pack; not the best design feature. Others have noted corrosion to the steel screws holding the pack lid on, I don’t know if this happened to ours.
So we’re waiting on a replacement battery, which is expected to take until 2023. In the meantime we’ve swapped the MX for another MS with a half decent range. It at least has free supercharging!
Watch this space.