Longer term Ohmmu experiences?

[dfwatt]

Instructions above on how to do a reset via the app and clear the warnings. I haven't tried it as I still have a V4 with the (+) coming in a month. Very odd why a 16 amp draw while parked with major draw items off. It's like the system spots a battery it doesn't like and tries to drag it down to failure to set off a warning. Like you, my V4 was working very normal for almost 4 days then all of a sudden the lockout occurs and it starts to drag down. I spotted it in short order and intervened before a dead battery. Now, it I had the V4+ and I got the change battery warning from the Tesla app, I could (I guess within bluetooth range) reset. Not sure how long that would last. At this point, ALL the lithium manufacturers should corner Tesla for a working solution since more than just Ohmmu is now affected.

Yeah it's just plain weird. Bizarre operating system. At first I thought maybe the 16 amp draw was rebalancing because sometimes the battery shows discharge when it's rebalancing. But clearly in this case it's not it's just being drained. I realized also it probably could not even be cabin heat because cabin heat is running off the main pack. In any case after resetting and recharging, the battery is now showing an overvoltage error at 14.2 volts. I'm wondering if the system overcharges the battery, then the battery management system prevents charging which it does when you get over 14 volts, and then the operating system rejects it and then drains it. It's f***** up whatever it is. As I mentioned before we had a similar bizarre and unexplained failure of the 12 volt system in our power walls in Florida with disastrous consequences. Tesla does not know what the f*** they are doing with 12 volt systems. Sorry for the bad language but this is just ridiculous.

PS has someone confirmed that this power cycling recommendations as posted above obviates the need to disconnect the dc/dc connector under the rear seat?

 

[Flybyglass]

Yeah it's just plain weird. Bizarre operating system. At first I thought maybe the 16 amp draw was rebalancing because sometimes the battery shows discharge when it's rebalancing. But clearly in this case it's not it's just being drained. I realized also it probably could not even be cabin heat because cabin heat is running off the main pack. In any case after resetting and recharging, the battery is now showing an overvoltage error at 14.2 volts. I'm wondering if the system overcharges the battery, then the battery management system prevents charging which it does when you get over 14 volts, and then the operating system rejects it and then drains it. It's f***** up whatever it is. As I mentioned before we had a similar bizarre and unexplained failure of the 12 volt system in our power walls in Florida with disastrous consequences. Tesla does not know what the f*** they are doing with 12 volt systems. Sorry for the bad language but this is just ridiculous.

My system routinely charges at 14.2-4v so the battery should be able to handle it. My V4 had a 14.7 limit on the case. This is like how many Tesla engineers to change a lightbulb?

 

[dfwatt]

My system routinely charges at 14.2-4v so the battery should be able to handle it. My V4 had a 14.7 limit on the case. This is like how many Tesla engineers to change a lightbulb?

That's weird because my battery will clearly block charging over 14.1. And by that I mean not the driving voltage from the system but the batteries internal voltage. At that point it stops accepting charging and I can see this in the control panel information. I can even elicit that manually by connecting and reconnecting the trickle charger multiple times until the float voltage starts to get over 14. Then the block charge indication is clearly visible. I wonder if that is part of what is eliciting rejection by the operating system. This of course is well above what a typical lead acid float voltage should be which is 13.5. In other words the BMS is allowing an extra half volt over that before it intervenes. But I still wonder if Tesla's got some crazy ass desulfation program running where they drive the voltage of the battery up because they think that is safe- it is in a lead acid if it's very brief. I wonder if Ohmmu knows whether or not Tesla is running a desulfation program. All the really top sources on lithium iron phosphate charging say that that type of charging program is deadly and bad news to lithium ferric phosphate chemistries, and should not be allowed to run. If that's what the battery management system on our batteries is detecting and disconnecting around, it would be easy for the idiots writing the code to have somehow interpreted that as battery failure.

 

[Flybyglass]

That's weird because my battery will clearly block charging over 14.1. And by that I mean not the driving voltage from the system but the batteries internal voltage. At that point it stops accepting charging and I can see this in the control panel information. I can even elicit that manually by connecting and reconnecting the trickle charger multiple times until the float voltage starts to get over 14. Then the block charge indication is clearly visible. I wonder if that is part of what is eliciting rejection by the operating system. This of course is well above what a typical lead acid float voltage should be which is 13.5. In other words the BMS is allowing an extra half volt over that before it intervenes. But I still wonder if Tesla's got some crazy ass desulfation program running where they drive the voltage of the battery up because they think that is safe- it is in a lead acid if it's very brief. I wonder if Ohmmu knows whether or not Tesla is running a desulfation program. All the really top sources on lithium iron phosphate charging say that that type of charging program is deadly and bad news to lithium ferric phosphate chemistries, and should not be allowed to run. If that's what the battery management system on our batteries is detecting and disconnecting around, it would be easy for the idiots writing the code to have somehow interpreted that as battery failure.

Ohmmu knows about the desulfurization causing issues over a year ago. I wonder if the BMS you have is not the final settings of the production version. I thought I read the BMS could be updated over the air (probably via the Ohmmu app which will be changing shortly).
Let Ohmmu support know exactly your findings. They are sending me a V4+ in about a month and it would be nice if these issues were finally settled. I also recall the BMS when it disconnects does so for 5 minutes then automatically resets. Not sure how it will work on the V4+.

 

[dfwatt]

Ohmmu knows about the desulfurization causing issues over a year ago. I wonder if the BMS you have is not the final settings of the production version. I thought I read the BMS could be updated over the air (probably via the Ohmmu app which will be changing shortly).
Let Ohmmu support know exactly your findings. They are sending me a V4+ in about a month and it would be nice if these issues were finally settled.

Good to know and of course not surprising if such a program existed they would be expected to be fully aware. I have not heard back but I have reached out. It is great to hear that BMS could be updated over the air via the app. That is for sure a highly desirable feature. Since problems started about a year ago I wonder if it was the initiation of the desulfation routines that triggered the original series of battery failures including a whole lot of lead acid failures in older batteries. Do you have any insight on that?

 

[Flybyglass]

Good to know and of course not surprising if such a program existed they would be expected to be fully aware. I have not heard back but I have reached out. It is great to hear that BMS could be updated over the air via the app. That is for sure a highly desirable feature. Since problems started about a year ago I wonder if it was the initiation of the desulfation routines that triggered the original series of battery failures including a whole lot of lead acid failures in older batteries. Do you have any insight on that?

I had so many notes from Ohmmu but I recall the desulfurization is what started the problems with the Ohmmu. It never used to do it. Tesla hired a new 12 volt guy and the tinkering started. The folks at Electrified Garage mention Tesla has been tinkering with the 12 volt profiles for years (way back on the S). There are some in TMC that will argue Tesla can do no wrong but in my case, I was having routine annual work done and Tesla proactively wanted to change my AtlasBX. Stated there were messages and I was clear it was probably from the Ohmmu swapping in and out. They were insistent of a swap so it should like their tinkering caused wide spread failures. Bases on some on here have had no issues with the V4+ and others have, I suspect Ohmmu put out batches with different programming to see what works best. They do read and answer, I just got some answers from a couple of weeks ago. I would put in the e-mail title something like Beta Feedback and ask it a software update for the BMS will be out soon.

From the IOS app store on the Ohmmu app : "This app is also used to perform battery resets and will be used to reprogram BMS settings in the future."

 

[dfwatt]

Well, I got those same 3 errors tonight. Car has been sitting for about 3 1/2 days plugged in. I would check the 12 volt charge level using my monitor and it was constant at about 13.3 volts with an occasional spike to 14.4 for a wake up. I got a warning from the Tesla APP in my iPhone notifications to "Replace 12 volt battery soon". (At least the app now warns you if away from the car).

Reinstalled my DiehardEV battery warnings cleared. 6 hour charge cycle started normally. I will post graphs below:

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Here is the charging monitor graphs the day prior and to point of failure:

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That for sure looks identical to what happened on my West Coast trip when the car sat for five six days and I got a VC front error code and car needs service warnings after about 3 or 4 days. So it appears that there's something about sitting that elicits this fault in the handshaking protocol between the battery and the 12 volt sub system. And then for reasons that remain to be explained, the battery drains quickly from the onset of that failure. Almost as though that failure is accelerated by what the car and its operating system are doing with the battery. That part is bizarre. Certainly a full battery even if it all of a sudden was no longer being charged in the car and was not being driven would not be drained in a matter of a day or so. It's almost as though Tesla somehow in their infinite foolishness decided that if the battery was suboptimal they were going to drag it to the floor quickly so that the owner had to replace it. Perhaps that's their upside down way of protecting folks from 12 volt failures on the road?

In any case the cumulative track record of failure on the part of Tesla to manage 12 volt systems including the consistent failure of the 12 volt system in the model S and then the reports mirroring our experience with powerwalls that the 12 volt system there also is prone to failure suggests that they've got the same idiots riding the 12 volt code across all these different battery packs. At least in the new cars they've gotten away from lead acid and have a proper lithium 15 volt subsystem. Maybe that's a confession that they don't know what the f*** they're doing with lead acid chemistries. Unfortunately we do not have an option to swap out 12 volt cells in our power walls. We just now know that if they're ever drained, they are effectively bricked until power comes back on. Great!

 

[Perscitus]

The 15v LVB and VCFront handshakes have their own issues too, so even that they can't seem to get right.

Not a great way to build confidence they know what they are doing with LFP 3s/Ys, especially given the recent 2022.40.x pre-heating and L3 charging fixes.

You'd think that with so much data flowing across the CAN buses, more than enough computing power and remote/local diagnostics available, this could all be easily handled.

 

[dfwatt]

The 15v LVB and VCFront handshakes have their own issues too, so even that they can't seem to get right.

Not a great way to build confidence they know what they are doing with LFP 3s/Ys, especially given the recent 2022.40.x pre-heating and L3 charging fixes.

You'd think that with so much data flowing across the CAN buses, more than enough computing power and remote/local diagnostics available, this could all be easily handled.

Interesting. I was not aware of difficulties with the new 15 volt subsystem but it does suggest a refractory incompetence in the low voltage arena. It's one of the things I wonder about with Tesla where you see exceptional competence in many areas and then absolute boobs operating as though they know what they're talking about in other areas. Overall we've had exceptional service on the cars, and with one notable exception, exceptional service on the Tesla solar systems including highly competent installation. And then occasionally you'll get somebody telling you something and insisting that it's true that is just plain total nonsense. It's a little bit like Elon himself where in his areas of competence he is exceptional but when he steps out of those he says things that are just plain idiotic if not grossly insensitive and stupid.

Perhaps it's what happens when people are praised excessively for their talent in one area they think that they are the smartest person in the room in all areas. Witness Novak Djokovic arguably the greatest tennis player of all time who can't figure out basic and well established Immunology worth beans and is a hardcore anti-vaxxer. Elon would do well to pay attention to those object lessons but I'm not sure anybody can tell Elon what he doesn't know. I know this sounds off topic but I believe that organizational culture mirrors leadership personality. Elon talks a lot about getting consistently and evenly excellent service and support but talk is cheap. Paying attention to the nuts and bolts of improving the rough spots requires hands-on monitoring and Elon is spread way too thin and is just way too distracted. Hiding feedback channels from users so that troubleshooting could be better informed does not help and although some might disagree with this, Tesla appears to believe that their data monitoring tells them everything they need to know about their systems. Just not true.

 

[Flybyglass]

Interesting. I was not aware of difficulties with the new 15 volt subsystem but it does suggest a refractory incompetence in the low voltage arena. It's one of the things I wonder about with Tesla where you see exceptional competence in many areas and then absolute boobs operating as though they know what they're talking about in other areas. Overall we've had exceptional service on the cars, and with one notable exception, exceptional service on the Tesla solar systems including highly competent installation. And then occasionally you'll get somebody telling you something and insisting that it's true that is just plain total nonsense. It's a little bit like Elon himself where in his areas of competence he is exceptional but when he steps out of those he says things that are just plain idiotic if not grossly insensitive and stupid.

Perhaps it's what happens when people are praised excessively for their talent in one area they think that they are the smartest person in the room in all areas. Witness Novak Djokovic arguably the greatest tennis player of all time who can't figure out basic and well established Immunology worth beans and is a hardcore anti-vaxxer. Elon would do well to pay attention to those object lessons but I'm not sure anybody can tell Elon what he doesn't know. I know this sounds off topic but I believe that organizational culture mirrors leadership personality. Elon talks a lot about getting consistently and evenly excellent service and support but talk is cheap. Paying attention to the nuts and bolts of improving the rough spots requires hands-on monitoring and Elon is spread way too thin and is just way too distracted. Hiding feedback channels from users so that troubleshooting could be better informed does not help and although some might disagree with this, Tesla appears to believe that their data monitoring tells them everything they need to know about their systems. Just not true.

It's not just Tesla. I worked for a Major Airline that if there was no data the problem didn't exist. I totally agree that feedback channels should exist but you can't give feedback to get the channels. I found a bug with the Tesla app that was waking both of my Tesla's multiple times an hour and the problem didn't exist until I submitted a maintenance request, asked for a log pull. Ok off topic. Maybe a tweet to Elon?

 

[mstatkus]

It's not just Tesla. I worked for a Major Airline that if there was no data the problem didn't exist. I totally agree that feedback channels should exist but you can't give feedback to get the channels. I found a bug with the Tesla app that was waking both of my Tesla's multiple times an hour and the problem didn't exist until I submitted a maintenance request, asked for a log pull. Ok off topic. Maybe a tweet to Elon?

Almost seems like it trips a process to deplete the battery almost like when you have a battery in your UPS Sealed Lead Acid failing and smelling rotten and boiling. That has happened at least 2 times to some family members with battery backups, and thankfully didn’t cause a fire. But, I’d think they would be executing some preventative steps to reduce what would happen if they ignored it. And we just happen to have a Lithium Battery tripping it.

 

[Flybyglass]

Is there anyone on this thread that has a Ohmmu V4+ that has had success without a reset? If so how long have you been using it.

 

[Perscitus]

Posted above, earlier in this thread. One sample size example here (and I believe there are some others). 6 odd weeks since install and no issues, yet. Waiting to see what happens when 2022.40.x finally pushes to this old early production 3.

 

[dfwatt]

This. I drive a lot. 2019 with 87k miles on it. I was concerned about battery failure so I just initiated a Tesla battery install. It was around 100 dollars and honestly. I’ll do this as a maintenance item every 3 years or 80k miles which ever comes first.

Understood in terms of your reasoning, but if you get 80K out of the stock lead acid with Tesla's endless fiddling and dic---- around with the 12V subsystem, consider yourself very lucky. Ours failed at 30K miles, and I am confident that they were brought down by the same 'experimentation' (putting it kindly) that induced the raft of issues with Ohmmu's LiFePO4 last fall. Specifically, the introduction of an ill-advised desulfation program that some boy wonder at Tesla introduced to prolong SLA battery life.

 

[dfwatt]

Well it appears that everything is back to normal after a simple reset - float voltage is 13.5 at most. Exactly what a lead acid battery would be and the system appears to be not doing anything weird - at least (knock on wood) since the reset.

Given that my system throwing the VC front 12 volt code and one other person's were reported during long stretches of multiple days of not driving I have to suspect that there's something about the handshaking protocol that happens during those long periods of the car just sitting and mostly asleep that causes the Ohmmu to disconnect and then get itself rejected by the 12-volt operating system. I had no problems for a full month and then Bang! - have to believe it's the long period of sitting and deep sleep with periodic refresh from the DC DC connection that sets the stage for some kind of trouble Any insights from the group?

 

[Flybyglass]

Well it appears that everything is back to normal after a simple reset - float voltage is 13.5 at most. Exactly what a lead acid battery would be and the system appears to be not doing anything weird - at least (knock on wood) since the reset.

Given that my system throwing the VC front 12 volt code and one other person's were reported during long stretches of multiple days of not driving I have to suspect that there's something about the handshaking protocol that happens during those long periods of the car just sitting and mostly asleep that causes the Ohmmu to disconnect and then get itself rejected by the 12-volt operating system. I had no problems for a full month and then Bang! - have to believe it's the long period of sitting and deep sleep with periodic refresh from the DC DC connection that sets the stage for some kind of trouble Any insights from the group?

View attachment 867724

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Advise Ohmmu. There may some simple adjustment needed to the BMS. The V4+ is over the air updatable in the future via the app and they may want to send an adjustment before they go into larger production at month end. Did you follow the reset guidance e-mailed out? I can think of 2 reasons the Ohmmu fails "handshake"to wake and recharge. Either the car is doing one of those desulfurization moves and that trips the BMC (although is should auto reset in 5 minutes). The other possibility is the car is supposed to wake on its own if a SLA battery gets below a certain voltage and initiate a recharge cycle. The Ohmmu "rests" at about 13.3 and the "float" voltage the car decreases to is about 13.3. The car never sees a voltage lower and doesn't initiate a recharge. It's possible if no recharge is needed after a few days the car isolates the battery from the system as being "unrecognizable" to what is expected. Just a thesis... My voltages were fine for days (car sat at 13.3) and then suddenly it was isolated with the 3 VCFront warnings and started discharging quickly. I interceded at 80%.

 

[dfwatt]

Advise Ohmmu. There may some simple adjustment needed to the BMS. The V4+ is over the air updatable in the future via the app and they may want to send an adjustment before they go into larger production at month end. Did you follow the reset guidance e-mailed out?

yes I'm still waiting to hear back from them about the first set of stuff that I sent them when I got the VCfront 12 volt code. No I just did my normal reset - do we have confirmation from anybody that that 'Battery-Centric' reset actually does a full power cycling - because my understanding is without removing the DC / DC converter connection, the car will not power cycle completely. Have you ever done that and had it clear VCfront errors? It's not like it's much extra trouble to do the normal reset process - takes like 2 seconds to pull up the rear seat and slightly detach the connector. if someone actually has confirmed that it clears codes to use the battery-centric reset process, I'll try that next.

 

[Flybyglass]

yes I'm still waiting to hear back from them about the first set of stuff that I sent them when I got the VCfront 12 volt code. No I just did my normal reset - do we have confirmation from anybody that that 'Battery-Centric' reset actually does a full power cycling - because my understanding is without removing the DC / DC converter connection, the car will not power cycle completely. Have you ever done that and had it clear VCfront errors? It's not like it's much extra trouble to do the normal reset process - takes like 2 seconds to pull up the rear seat and slightly detach the connector. if someone actually has confirmed that it clears codes to use the battery-centric reset process, I'll try that next.

No I only did a removal and swap back to an AGM. I have a V4 not +. But Ohmmu published a reset procedure a couple days ago that can be done from the app while in the car. No idea on behavior doing app battery reset.

From Ohmmu

"To do a reset, we will eventually have a module within the app that walks owners through the process and will just have a button that says "disable" which will take care of what is needed. For now, please follow the procedure below: Thank you.

Power Cycling the Vehicle
If your vehicle demonstrates unusual behavior or a nondescript alert is present, you can try power cycling the vehicle to potentially resolve the issue.

• Shift into Park.
• On the touchscreen, touch 'Controls' > 'Safety & Security' > 'Power Off.'
• Wait for at least two minutes without interacting with the vehicle. Do not open the doors, touch the brake pedal, touch the touchscreen, etc.
• Launch the Ohmmu app to connect to the battery, ensure/charge up so state of charge is >15%
• Turn off Enable Charge and Turn off Enable Discharge.
• Wait 10 seconds and press brake pedal to ensure car does not wake up (that car is fully powered off)
• Wait 30 seconds and then Turn on Enable Charge and Turn on Enable Discharge
• After two minutes have passed, press the brake pedal to wake the vehicle.

**Please note the enable charge and enable discharge switches will tell the BMS microcontroller to, in effect, "block" charging or discharging or "allow" it. If charge is enabled, for example, the BMS will leave the battery internally connected when current is at 0.0A or anything higher (positive current going into the battery), but if charge is disabled, the BMS would react to any current greater than 0.0A and internally disconnect it. If charge is disabled, then, the battery can't charge but it can discharge and will eventually be dead. Please be mindful toggling these switches in the app as they may leave the battery in a state where it is blocking all charging."

 

[Perscitus]

Aside from pinging Elon about a user configurable switch for LVB setup, maybe greentheonly can shed some light on config/code diffs between legacy 12V lead acid LVB and newer 15V lithium-x-ion LVB. Does anyone have means of contacting him via Twitter or else?

My thinking is perhaps whoever is monkeying around with the LVB code/diagnostics, etc has NOT enabled the desulf proc for the 15V LVB on the newer cars? And if so, there should be a config for that, with a different path for the code to follow.

Obviously we dont want the cars to think they are running the full 15V LVB hardware config or Teslas own 15V LVB... but just to stop some of the lead-acid checks, fail-safes.

 

[Flybyglass]

Aside from pinging Elon about a user configurable switch for LVB setup, maybe greentheonly can shed some light on config/code diffs between legacy 12V lead acid LVB and newer 15V lithium-x-ion LVB. Does anyone have means of contacting him via Twitter or else?

My thinking is perhaps whoever is monkeying around with the LVB code/diagnostics, etc has NOT enabled the desulf proc for the 15V LVB on the newer cars? And if so, there should be a config for that, with a different path for the code to follow.

Obviously we dont want the cars to think they are running the full 15V LVB hardware config or Teslas own 15V LVB... but just to stop some of the lead-acid checks, fail-safes.

Taking it further, why do some cars with V4+ been normal for several weeks but others get warnings after a few days? Different beta test internal BMS settings?