I watch the car via teslafi and dont check on the tesla app to verify its sleeping. Also sentry is not on. Car slept fine before swapping the battery. Checked again this afternoon on if it was in a death spiral and its staying normal so far. Car just wont sleep.
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Ohmmu 12V Battery Feedback
- Thread starter LasVegas2019
- Start date
Capacity has never been the issue here. The only thing Ohmmu is trying to do is make the Tesla charger think this is a healthy lead acid battery, instead of a Lithium battery so it doesn't throw errors. In the past Ohmmu has actually shrunk the capacity of batteries trying to accomplish this. A "larger" battery is not a good thing in an EV- it adds weight for no real purpose.
I wouldn't make any assumptions until about 48 hours. Like I said, I've seen my car stay awake for a long time after replacing a battery, and I always assumed it was running a battery test/calibration.
So the car is finally sleeping after 48 hours like you said. Now guess we wait and see if it eventually does the death spiral again or not.
What car software and when was battery built? Also, check the advanced page of app for any red indications. Running FSDBeta 10.69.25.2 (2022.44.30.10) and battery has been in for about 9 weeks with normal indications. Survived a brief period at -11F no issues but car always plugged in while not in use and preconditioned on cold departures.
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Car is on firmware 2023.2.10 and the app had no red indicators, just said battery was discharging. The tesla app sent me a push notification that 12v battery needed to be serviced. I had noticed that the car before was not sleeping again and was staying awake after charging and parking. It must have noticed some odd voltages from the 12v battery is my guess and kept testing it. Really have to wonder if there will be any way to mitigate this with a lithium battery, how can you trick the tesla system that is checking for lead/acid characteristics with a lithium battery? Im kinda at the point that this battery will be used for other things. If eventually ohmmu figures out how to trick the tesla system to not rejecting their battery, thats how its going to be.
The only other place to see what was going on would be put it onto service mode and check the LV battery. However, Now I'm wondering not Tesla changed the charging profile again. In my case, the 12 volt (Ohmmu) is used to wake up the car, then it charges up to about 14.6-14.8 volts. Sits a bit then discharges down to 13.4ish volts and then shows now amps in or out until the next startup. Let Ohmmu know. The next update is supposed to be able to update firmware and pass along battery data files back to Ohmmu is needed. I think I'll put a charger on my backup DiehardEV just in case. BTW advise is sleeping behavior returns to normal. As I write this I checked again and no change in how mine cycles BUT I am on older software.
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You guys still hanging in there with Ohmmu batteries should get a medal.
…. Or a straight jacket. Not sure which.
...But a Lead Acid battery might fail without warning every 4 years. so I run a Lithium battery that throws errors every week to make sure the warning system is working!
Well we paid for the battery so why not keep trying to get it to work if ohmmu hasnt given up on them i guess?
Ohmmu has not given up. They are working right now on an app update that will enable battery firmware updates and log info on issues that can be sent back to Ohmmu. On the FSD branch the software has been working OK with the Ohmmu. Hoping that continues but Tesla may have tinkered again.
Stanwood Steve
2018 Performance Model 3
I was just contacted by Ohmmu about receiving a new battery with the version 4+ BMS. I filled out their order sheet and I received confirmation this morning that the new battery has been shipped. I assume they'll be including a label to return my old battery after I receive the new one. This was at no cost, by the way. Has anyone else received the version 4+ battery and had any experience with it?
I have the V4+. Worked great for 10 weeks until temperatures dropped into the low 30's (F). What I observed was charging behavior was a large grain at start (approx -25 amps for a few seconds) followed by charging at about 9 amps until battery at about 14.8v. Then resting. (all of this using the Ohmmu app). After a bit the car would draw from the battery at about 5-8 amps until the charge level dropped to about 13.4 volts and stop. After that the battery would rest until next drive. No amps in or out. Looking at the service mode menu under LV battery, I would note the Tesla would alternate between charging at .1 amps to discharging at .1 amps. Maybe even less. When temperature dropped into the 30's the Tesla flagged bad battery and allowed 12.5 volts un til stopping. This drained the battery to about 12%.
I should mention my build was an early December 2022 and the firmware may be updated with your build.
I could not do the Ohmmu app reset as I was below 15% that is in the procedure. I removed the Ohmmu V4+ placed on a lithium battery charger at 1 amps. No real charging. So I connected a 6 amp conventional slow charger and raised the Ohmmu to 35% on the bench. Reconnected the 1 amps slow charger (in a cold garage around 40f) and left overnight. I return the Ohmmu was at 34% (it dropped 1% on the charger) and the charger showed fully charged? Reconnected 6 amps slow charger and battery continued charging until Ohmmu app said 100% and it was at about 13.5 volts. My conclusion, an adjustment to the battery was needed. The Tesla reacted correctly sensing a none charging battery and flagged it. I contacted Ohmmu with the findings. In the latest support section they mention:
"IMPORTANT NOTES:
- We have identified the issues causing these errors.
- Ohmmu is currently developing a hardware revision (Rev4+) to resolve this issue for existing customers, which should be available at the end of June 2023."
Since the V4+ is back available, I would guess it has been updated from the build. I would ask. Meanwhile I'm waiting for the app revision. Up until the cold weather failure it worked flawlessly and since the recharge it is sitting on the shelf still at voltage and I should mention all the indicators in the app were always green showed no internal failures. It just would not charge at low amps/low temps.
One huge fly in the Ohmmu ointment has been the sluggish communication through Bluetooth app and the way in which the battery can actually be turned off in terms of receiving charge while it indicates on the interface that it is accepting charge. The app needs resetting to be reliable at all. This is a huge issue as far as I'm concerned because it leads to scenarios in which you think the battery is in its normal configuration and in fact it is blocked from charging or discharging or both. This of course creates all kinds of problems as the Tesla operating system sees either of these as indices of battery failure. I no longer trust what the Bluetooth battery interface is saying unless it is initialized from scratch. And although I'm not sure about this I believe it's period of reliable communication is relatively short before it needs to be reinitialized. Not sure what that interval is but it's not 5 - 10 minutes.
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iwannam3
Active Member
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