12/12 built P85, 3rd owner, battery replaced under warranty in 2018 with a new one. Should I keep the car?
100% charging is 238ish miles.
One might naturally "think" a new pack in 18 (5 years old) would be okay for the next 5ish years. But there are a lot of variables and nearly no visibility to the real reliability stats of the entire fleet and various revisions.
Higher moisture exposure situations likely shorten longevity. You are in SoCal but if near foggy salty ocean air, park outside with moisture condensation, car wash everyday and dump water on top of front battery pack (near fuse and front hump) then maybe lower longevity.
Recently seen a 2022 manufactured new MS pack that has been rebuilt once. Very latest new packs might be dealing with obsolete lower volume manufacturing problems. Don't really know.
In general, Tesla battery pack is not complex design wise. However, it is numerically complex component wise. 14k+ ultrasonic welds to 7k+ cells is such numerical complexity susceptible to any manufacturing assembly variation.
But out of warranty with $15k-$22k battery replacement cost means car is a battery failure away from becoming worth $5-$10k. Will always be a gamble. Failed HV battery out of warranty battery cars will probably be close to $5k towards end of 24 with 2016 cars coming off warranty and adding to the HV battery failure noise. HV battery failure noises are really low on in warranty cars for obvious reasons.. But out of warranty repair price shock prompt a lot of complaints and postings. Impact to out of warranty MS price seems quite significant and rapidly heading downwards. Probably even stunting some new Tesla sales too as noise gets louder.
For sure. I think you could get a lot more for yours than what a simple trade in quote is and you are probably better off selling it now for that higher price before something major goes wrong. Mine is currently dead and I'm probably looking a drive unit replacement out of warrantty. This will be its 3rd one in 100k miles. There's clearly a defect in the design and as a result I really don't think we should be paying for them, but what recourse do I have?
Was going to mention the potential double whammy $7k+ LDU failure replacement beyond the battery but sounds like you already know.
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Beyond battery and LDU, seems like other failures are more palatable at say < $2k each. Various HV device failures (battery heater, cabin heater, AC, DCDC) likely from windshield water run off dump are probably $1k - $2k.
One risk with older out of warranty cars and unlimited supercharging is to think you can travel long distance for low cost based on unlimited super charging. Just about ANY of the aging HV component failure from long term water+electricity don't mix issues = a dead car and absolutely no prior warning. But if not HV battery, at least its towing to SC near breakdown location + $2kish repair. But vacation is probably ruined.
More locally used car, low moisture locale and car use, having ~$10k HV battery rebuilder nearby, and hoping Tesla's recently revised rotor coolant delete LDU surviving longer can probably provide more confidence to keep. For me personally in Seattle, I don't drive in rain (a lot of the winter and need to check weather report always haha) have DIY knowledge on fixing battery, LDU, HV components, might be worth taking the risk. But probably no long distance road trips even if I recondition the battery (open+refurb) have knowhow+tools to get some failed HV system car running. Aging battery cell shorts are unfixable without complex battery rebuild + reconfiguration.
Anyway, a lot of failure mechanisms on older MSs to consider. Probably no single right answer.
