Yes my V1 is long gone. Good thought and generous one to give to another EV owner. If I knew one I might donate my oldest which still works fine. I think I'll keep the V4 earlier version as a backup spare in case Tesla's suicide routine completely nukes the battery and I need to put something else in temporarily.
The problem is that this worked flawlessly for three years until Tesla started experimenting with what are called 'desulfation' routines in the fall of 2021. These routines are dangerous for and completely unnecessary on lithium iron phosphate. They may have some modest value in prolonging battery life by desulfating lead plates on lead acid batteries, but the BMS on our batteries tends to see this is dangerous overcharging and then disconnects. Then the 12 volt subsystem on the Tesla sees the battery as defective, begins aggressively discharging it (what we call a suicide routine) and then gives you a code that the battery needs service. Why in the world Tesla would think that there is value in aggressively discharging a battery that may have problems is beyond all of us. There may be additional variables in the failure of the battery handshake with the Tesla 12 volt subsystem because all of us have experienced more frequent error codes when the car sits for a long period of time.
The OEM Lead acid battery is like $90. Its at least 3-4 times cheaper than the alternative being talked about in this thread. Its absolutely self installable, but Tesla charges about 30-40 dollars labor to install it, even via mobile service. Thats not a "serious revenue stream".
I cant clearly see the model in your screenshot, so I will ask. Was that a model 3? this is the model 3 subforum, and any mention of pricing is pointed entirely at that model and not applicable to any other model.
While I understand why you're upset, what you are promoting is disinformation here. Tesla does not lock out updates, and it does not detect incompatible batteries, it's simply that while there is an active 12 volt error code, you cannot do updates. Please don't spread disinformation as a way of retaliating for an unsatisfactory experience with a merchant
Well the V4+ had been working perfectly for about 10 weeks then today for lack of a better word suicide mode. Got a message on my watch to replace 12 volt battery as I sat for a movie. Came out 2.5 hours later and 12%. Too low to attempt a reset per Ohmmu's instructions to removed and swapped into a DiehardEV I had on the shelf just in case. All Ohmmu indications were green in the app and viewing service mode it showed the photo below. No reason why and nothing different for weeks. Forwarded information back to Ohmmu.
Looking at this data screen, it appears if the car doesn't like the battery indications it stops charging hence the output at 12.58 volts. As a result with low output and voltage demands the battery just discharges. Normal indications would be a PCS output around 14.7v. I could not trickle charge the Ohmmu allow temperatures (under 40f) and 1 amp. I have a 6 amp charger and that one brought it back to full. It may be the Ohmmu BMS wont accept very low charges (under 1 amp) at low temperatures and hence the the fault readings. I have forwarded that information to Ohmmu as this may only need a firmware update. Nothing had changed in the car in 10 weeks other than temperature.
Right sometimes I feel people search for a problem and make a complicated solution. Just do preventive maintenance and replace the oem battery at set times even if your the 12v is not showing code it needs replacements. Literally it’s 1/4 the cost and Tesla will replace them while you sit at home sipping coffee or while you work and your car is in the parking lot. Just got this done after 3 years for a little over $100. I’ll replace them again in 2-3 years whether the car tells me to do so or not.
If you get three years of reliable operation from the OEM LA battery without any codes, you're an outlier on the end of the curve. 2 years looks more possible. 12-18 months, probable. By those numbers your approach does not look like it saves any money at all over an aftermarket battery that admittedly requires jiggering and resets but that lasts 4-5 years.
