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12v battery configuration issue draining my HV battery


Oct 6, 2018
San Jose
I have been noticing a lot of drain with my battery over the last few months, initially I thought it was phantom drain as I was charging every 2 weeks. I started noticing that I was getting only 100-120 miles per 90% charge of a 70kwh battery.

I finally reached out to Tesla, they initially rejected the claim that nothing was wrong and after some diagnosis they confirmed that the car was waking up over and over to charge 12v(after they replaced the 12v battery few months back). The guy who diagnosed the car over the phone asked me to get the car for service. I raised a query about compensation, the service guy over the phone rejected the idea of compensation as I didn’t raise this issue before. He was also very rude that I was asking for compensation (I mean I should have lost 1000-2000kwh after they replaced the 12v due to this issue), he blamed me for not being this issue to Tesla earlier :)

Any ways, I took the car to the service and they initially mentioned that it was due to a SW bug, I asked the service person to put that in the notes, as they didn’t leave any notes. After my request, He changed his messaging to “wrong 12v batter configuration during previous install and due to which HV battery was trying to charge the 12v”

I felt Tesla was trying to hide this issue with false messaging and trying hide this under the rug, I have reached out to them for compensation for lost of power over the last few months due to their mistake. I also didn’t like the way they dealt with this issue, with wrong reasonings, pushing the issue on me not diagnosing it earlier (the car never showed any alerts)

Overall disappointed with the way Tesla dealt with this issue

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