Ohmmu 12V Battery Feedback

[lUtriaNt]

With how you went through this thread and disliked every single post that was remotely critical of Ohmmu it makes me think you work for Ohmmu or something.

If it was only 60 batteries and an isolated incident they wouldn’t be on version 3 of their battery after having issues in late 2020 as well. Many threads on those issues as well.

Trading one set of issues for another isn’t something I’m interested in and many others feel the same way here as well.

if i don't agree with posts i dislike. that's what the icons/options are for sir.

i got that data from the company themselves. you are also free to ask them and hear it from them. you can even reference my post. could there be more? sure, but at the time i asked them thats what i was told.

you forget this enthusiast forum is a small microcosm of the hundreds of people who have these batteries in the wild. squeaky wheel gets the grease so if 3 or 4 people come onto a thread and say they have an issue with something, people suddenly think its the end of the world and everyone has the issue. then people start dog piling onto these posts , causing potential purchasers to be in fear.

i do not have the issue with the battery and it has been worth the investment. i got on board with the battery april 2020 and i got the rev 2 when they were shipping and its been solid. this is my experience. ive got fsd beta and am constantly getting updates and the battery has been a champ.

you cant speak to the mindset of others, and i did not know you were made the spokesperson for the thread sir. my bad...

other threads -- ive been on this site for a couple years and ive read every ohmmu thread. even in the other car subs on this site. overwhelming majority of people have had good use of the battery. tesla make changes to their system and ohmmu have been proactive on getting to the bottom of it. that is top flight customer service and what i expect.

there are other options and no one has to get this battery at all. some of you mugs on here jawin' tryin' to justify why you ain't gettin' one -- no need to tell people why you decide not to get one. this thread was setup initially as a way to get direct experience from actual owners rather than people trying to bash the product.

feel free to downvote this post to give you that endorphin rush you get when you see my posts...

 

[Jeremy3292]

there are other options and no one has to get this battery at all. some of you mugs on here jawin' tryin' to justify why you ain't gettin' one -- no need to tell people why you decide not to get one. this thread was setup initially as a way to get direct experience from actual owners rather than people trying to bash the product.

The thread is titled "Ohmmu 12V Battery Feedback." You just don't like that people are giving *bad* feedback lol.

You also went through and disliked every *actual direct experience* of users on here that was bad also. So because *you* personally haven't had any issues with the battery, doesn't mean there aren't issues that lots of people on here have voiced their displeasure with.

It seems you are huge Ohmmu fan and that's awesome, good for you.

 

[Flybyglass]

There is a current issue with the Li 12v battery for me now since Tesla updated their equalize charger to 14.8v in the car. It has bricked the safety switch in the Ohmmu battery which has taken out heated seats, heated air, and sentry mode for the car. It also cannot receive updates due to the softwares change and Ohmmu has been dragging their heels on getting a fix for the past 2+ weeks. If they can’t support their batteries and gives the car all the functions it needs, no one should buy from them. This especially sucks during winter. I am currently very pissed at them for being so slow to respond with a fix to this.

Did you go through the reset procedure outlined on the Ohmmu website until the correction modules can be sent out?

 

[Pied]

Did you go through the reset procedure outlined on the Ohmmu website until the correction modules can be sent out?

Not the poster of this, but I did the reset and was able to update the software. The errors came back a few hours later and my heated seats and sentry mode are not working again.

I don't drive my car much, but for those who do it sucks.

 

[Flybyglass]

Not the poster of this, but I did the reset and was able to update the software. The errors came back a few hours later and my heated seats and sentry mode are not working again.

I don't drive my car much, but for those who do it sucks.

Advise Ohmmu through the support section.

 

[davidviolin]

I have a similar issue with the MPP earthx 900 battery. Since I installed the (very nicely) machined brackets that MPP supplies with the purchase, to hold the battery which is alot smaller, its very difficult to just swap back to the old lead battery. Is there a separate thread on the MPP battery?

I reached out to MPP and they told me to charge the MPP battery back up to 14.8 volts, hard reset the car with disconnecting the HV battery and see what happens. I did that yesterday and today when I woke up the car had lost 8 % SOC. Anyone else having similar issues?

This is very annoying, especially since I cannot just pop the old lead acid back in, making my car undriveable.

 

[Flybyglass]

I have a similar issue with the MPP earthx 900 battery. Since I installed the (very nicely) machined brackets that MPP supplies with the purchase, to hold the battery which is alot smaller, its very difficult to just swap back to the old lead battery. Is there a separate thread on the MPP battery?

I reached out to MPP and they told me to charge the MPP battery back up to 14.8 volts, hard reset the car with disconnecting the HV battery and see what happens. I did that yesterday and today when I woke up the car had lost 8 % SOC. Anyone else having similar issues?

This is very annoying, especially since I cannot just pop the old lead acid back in, making my car undriveable.

It sounds like any battery with a built in BMC (any lithium battery - other than Tesla's factory Lion) conflicts with the latest software. It has something to do with Tesla now doing an over charge test of the 12 volt battery and the Lion BMC not liking the test and the Car interpreting as a battery failure (when it is really OK). Ohmmu is developing a correction module to be installed and for future battery buyers the changes will be built into the battery. I know the Ohmmu's BMC will shut off charging if the Ohmmu detects an overcharging (makes sense as a protection). That overcharge protection automatically resets within the Ohmmu after a few minutes. (see Ohmmu reading 0.0v on Multimeter) .Then it looks like Tesla decides the 12 volt has failed (remember Tesla is looking for a Lead battery) and isolates charging it hence the messages of reduced availability 12 volt since now you would be relying on the DC-DC convertor to carry the entire load with no buffer via a working battery. This is my best guess based on reading all the support memo's at Ohmmu. Tesla had a recent engineer decide to add 12 volt battery testing to the software revisions and then all the problems started. Of course I could be totally wrong here...

 

[davidviolin]

It sounds like any battery with a built in BMC (any lithium battery - other than Tesla's factory Lion) conflicts with the latest software. It has something to do with Tesla now doing an over charge test of the 12 volt battery and the Lion BMC not liking the test and the Car interpreting as a battery failure (when it is really OK). Ohmmu is developing a correction module to be installed and for future battery buyers the changes will be built into the battery. I know the Ohmmu's BMC will shut off charging if the Ohmmu detects an overcharging (makes sense as a protection). That overcharge protection automatically resets within the Ohmmu after a few minutes. (see Ohmmu reading 0.0v on Multimeter) .Then it looks like Tesla decides the 12 volt has failed (remember Tesla is looking for a Lead battery) and isolates charging it hence the messages of reduced availability 12 volt since now you would be relying on the DC-DC convertor to carry the entire load with no buffer via a working battery. This is my best guess based on reading all the support memo's at Ohmmu. Tesla had a recent engineer decide to add 12 volt battery testing to the software revisions and then all the problems started. Of course I could be totally wrong here...

Yes I think this sounds right. I think its possible this started with the last December. I also think the reason is them moving to Lithiums in the 3's and Y's. They require higher voltage, and I also read the windshield washer fluid pump being changed to 15.5 volt, there might be two different version of the 12v battery firmware, one for the old AGM and now one for the new Lithiums. Since my car was made in 2018, its assuming that it has an AGM battery and according to that, software thinks its something wrong there. This was not an issue before the split between AGM and Lithium. Just a theory, but seems likely given the issues started occuring once they started using OEM lithiums in the 3 and y.

 

[Pied]

Fyi, I contacted Ohmmu today and the current estimated timeline for distribution of the module is end of this month.

 

[Skione65]

Putting my OEM back in today. Ohmmu is throwing codes every few days and I’m tired of the resets. Especially in winter sub zero temps and at most inopportune times. Fix can’t come soon enough.

Ski

 

[Flybyglass]

Putting my OEM back in today. Ohmmu is throwing codes every few days and I’m tired of the resets. Especially in winter sub zero temps and at most inopportune times. Fix can’t come soon enough.

Ski

Ohmmu said the model will be out this month and an updated battery in late April.

 

[Skione65]

Ohmmu said the model will be out this month and an updated battery in late April.

Thanks….copy that. I’ve been talking to them as well. They’ve got a couple hundred modules they’re waiting on. Delayed a couple weeks due to Spring/New years festivals overseas where the modules/PCB boards are being built. Then Batteries in Mar/Apr as you mention.

Ski

 

[Nightdown_fox]

Threw a cheap BJs 51r in there until this all gets sorted out. The errors were starting to stack.

Update got downloaded from spouse messing with the app, but the car wouldn’t update with the battery warning even with a full reset and popping main power connector. Since the update downloaded, it would repeatedly ask to schedule it every drive despite it not being able to complete, then the battery error would repeatedly pop up and block other info during the drive. This all compounded with the winter weather recommendations screen, so there were an annoying amount of distractions and screen presses every single drive. Most importantly, my range took a huge hit — significantly worse than last winter. May have been able to wait another month or two if this were in the summer, but the range hit sealed the deal.

Everything is back to normal with the cheap 51r. That module can’t come soon enough. The swap out reminded me how light the Ohmuu is though… feels like a lunchbox in comparison.

 

[Pied]

I'm still holding out. I am planning to put the ohmmu on a charger this weekend. My guess is with the error, the battery is not being charged by the car. Could be the reason why it the reset didn't work?

 

[Flybyglass]

I'm still holding out. I am planning to put the ohmmu on a charger this weekend. My guess is with the error, the battery is not being charged by the car. Could be the reason why it the reset didn't work?

You are correct. Tesla started doing over voltage charging checks on the 12 volt battery with latter softwares. The Ohmmu BMC saw that and disconnected for a few minutes thinking it was an actual overcharge event. The car would see that and put out failure messages when the Ohmmu was doing as designed. The updated version and module will not go offline with the over charge test. The battery would continue to charge after the failure messages were cleared until the next over charge test event.

 

[Lester Green]

I've had an Ohmmu 12V battery in my 2018 Model 3 since December 2021 with no issues, until today. Now I am receiving several electrical alerts. I did perform a reset and it did not clear the errors. I performed a second reset and the alerts are gone, for now. I did see the article on Ohmmu's support site Tesla | Model 3 / Y | "Schedule service to replace low voltage battery" Error - Ohmmu Support and it sounds like I should receive a fix soon. This is very concerning and I'm starting to wish I just stuck with an OEM battery. Hopefully Ohmmu resolves this quickly and pushes those thoughts out of my mind. It seems like this could become a cat and mouse game.

 

[lUtriaNt]

I've had an Ohmmu 12V battery

whats your software version? are you in fsd beta?

 

[Lester Green]

whats your software version? are you in fsd beta?

I am not FSD. I upgraded to 2022.4.5 last night (after performing my 3rd reset). The problem first occurred with 2021.44.30.7

 

[Lester Green]

I have decided that I do not want to deal with the cat and mouse game between Ohmuu and Tesla. I am asking for a refund and I am getting a Tesla OEM battery installed on Tuesday. I hope I can get my money back. I did pay with PayPal so maybe they can help. This battery is not truly compatible with the Model 3.

 

[bobby g]

Wondering if the oem Li will work for us. I have an 2018 model 3 as well. I am going to need some 12 volt replacement pretty soon.

Thanks to all of you for doing the field testing on the Ohmuu