Ohmmu Battery & 2020.28.6 update

[Matsayz]

the battery error only prevent you from INSTALLING the update until you reset the HV - you still will get the download.

i dont think the cabin overheat protection is tied to the 12V error. the car still charges the battery and the battery is still strong at 13.x volts. i think the error indicator is just a heads up and is not preventing other features or equipment from working normally.

whilst i park in a garage it can get hot in there and ive seen model 3 cabin temps get up in the 90s but never in the 100s!!!

Here in Vegas both our 3 & Y will frequently see 103*F in the cabin while it’s 103-105*F in the garage. I attached a picture of what it’s like right now.

I would like to buy this battery once this gets figured out as my Model 3 is just over a year old and did the Colorado winter then we moved here to Vegas for all of the Summer fun. When we’ve lived in Vegas and Tucson before the 12Volt batteries in our ICE cars lasted about 1-2yrs. Part of the fun living in the desert!

 

[Knightshade]

Straight from service advisor: 12 v is covered 4 year 50K miles. No over the counter sales of batteries for self installation. Out of warranty battery + installation $350. PDX Macadam YMMV

At least they let us buy and install wipers air filters.

So a service advisor lied to you. Shocker.

https://epc.tesla.com/#/systemGroups/47334

That's the Model 3 parts catalog for the 12v battery system.

Notice how the very first part list is the 12v battery, and it explicitly lists it available over the counter, no VIN required.

 

[luke68bird]

Just another update but no news. It's been 1 month, 2 software versions and 3 reset attempts. Still 12V needs replacing warning. The car has not left me stranded and it's over 2 years old, without Ohmuu battery the car may have not booted up with this age and Texas heat.

 

[Wennfred]

Just took a ride in the Model 3, still no battery error, Ohmmu installed April 2019, SR+ HW2.5 and currently on 2020.32.3 with 21,000 miles, so I am waiting for 36.0 to see if I will get the error also. If not then I’m guessing it’s only happening to newer batteries?

Fred

 

[lUtriaNt]

updates from Ohmmu :

Alongside our efforts for a software resolution with Tesla we have also been working on a hardware resolution we can deploy ourselves. We are in the final phase of testing which is expected to be complete on 9/10-9/11 (by end of this week). The results of this testing should green-light our new production-line which will be building a new revision of the Model 3 battery. This revision will not be flagged by the new Tesla alert system and is more compatible with their alert system than our current version overall. Note, the battery itself isn't "better" it is simply more compatible with their testing criteria in vehicle.



After the revision is complete and validated production will commence and we will be offering a free swap-out to anyone with an affected vehicle and our battery. We will send a replacement battery and you send us back the current one in the box the new one comes in (save the adapters!). The expectation for this process to begin shipping (if all goes well) is 4-6 weeks from now.



In the meantime, your vehicles are fine and the alert is only an alert, it doesn't actually have a functional affect other than preventing software updates.



Thank you for your continued patience and understanding in this time. As always any ideas, questions, concerns, comments please don't hesitate to reach out to us and let us know! It has been very helpful for us to know what is going on with as many vehicles as possible, it can get overwhelming keeping up but we are doing our best as a team here!

 

[Wennfred]

Check your email, this just in:

 

[alee]

I hope this new one is field updatable herein. Even though they're working with Tesla, who's to say this new fix doesn't get undone in a later revision.

Looking forward to seeing what comes.

 

[grmdl3]

I'll be really curious what their hardware solution is.

 

[Phlier]

I'll be really curious what their hardware solution is.

My guess:

They re-program the BMS to only take a certain amount of power from the car, and only so often. This is to avoid tripping the "bad 12v battery" code in the car.

IMO, Tesla has code that monitors how much current the 12v battery takes, how often it takes it, and length of charging sessions. Once certain parameters are exceeded, it throws the 12v battery warning.

As long as Ohmmu's BMS is programmed to stay within those parameters, no warnings will be thrown.

But again, that's all a guess.

It would be nice if Ohmmu included a micro USB port on the battery to flash new BMS firmware.

 

[alee]

It would be nice if Ohmmu included a micro USB port on the battery to flash new BMS firmware.

100% agreed... the permanent solution is adaptability unless Tesla actually includes a "battery type" in the Service menu, like they do for changing wheel sizes. I'd hate to swap a battery and find out 8 months later Tesla has again altered their algorithms.

 

[neurocutie]

any reason Tesla shouldn't be urged to switch to an Li 12V battery themselves? changing the AGM 12V every 2 yrs particularly under warranty can't be good for Tesla, nevermind the owner...

 

[alee]

any reason Tesla shouldn't be urged to switch to an Li 12V battery themselves? changing the AGM 12V every 2 yrs particularly under warranty can't be good for Tesla, nevermind the owner...

Impact to the bill of materials, volume sourcing, etc. Even at $100 more per unit, you'd be looking at over a million in added cost, assuming you could get that many batteries. Realistically it's probably more than that. Lithium 12Vs are still somewhat exotic - certainly not many of them in the aftermarket world.

 

[MP3Mike]

any reason Tesla shouldn't be urged to switch to an Li 12V battery themselves? changing the AGM 12V every 2 yrs particularly under warranty can't be good for Tesla, nevermind the owner...

It costs ~4x more? There is already a shortage of Li cells? Most last longer than 2 years?

 

[neurocutie]

Impact to the bill of materials, volume sourcing, etc. Even at $100 more per unit, you'd be looking at over a million in added cost, assuming you could get that many batteries. Realistically it's probably more than that. Lithium 12Vs are still somewhat exotic - certainly not many of them in the aftermarket world.

$100-200 more per unit is easily offset by having to replace the AGM 12V at least once during the warranty period. As far as 12V Lithium, don't most 12V car electronics work perfectly fine at 10.8-11.7V (3 Li cells in series)? So shouldn't be that exotic. If Ohmmu can sell theirs for $440, then cost to Tesla in quantity must be $200 or less. Not that much more than a couple of AGM's.

 

[jjrandorin]

$100-200 more per unit is easily offset by having to replace the AGM 12V at least once during the warranty period. As far as 12V Lithium, don't most 12V car electronics work perfectly fine at 10.8-11.7V (3 Li cells in series)? So shouldn't be that exotic. If Ohmmu can sell theirs for $440, then cost to Tesla in quantity must be $200 or less. Not that much more than a couple of AGM's.

That would be assuming that "everyone" needed a 12V replacement in 2 years, and "everyone" doesnt. I also thought I saw that tesla charges lik $80-100 for the OEM outside of warranty.

If even 50% people need to replace this under warranty, that means 50% dont, and you didnt speend $100 more per unit times all the cars you make. its not "easily offset" unless every single car had to have them replaced.

 

[neurocutie]

That would be assuming that "everyone" needed a 12V replacement in 2 years, and "everyone" doesnt. I also thought I saw that tesla charges lik $80-100 for the OEM outside of warranty.

If even 50% people need to replace this under warranty, that means 50% dont, and you didnt speend $100 more per unit times all the cars you make. its not "easily offset" unless every single car had to have them replaced.

Remember to factor in the labor and other service costs associated with making an in-warranty replacement, in the field or at a SC... Nevermind owner satisfaction and "street-buzz"... if competitor EV dealers can somewhat truthfully say that southern state Tesla owners can expect to have to replace the AGM every 2 yrs, that is not going to be a good look for Tesla...

 

[alee]

As far as 12V Lithium, don't most 12V car electronics work perfectly fine at 10.8-11.7V (3 Li cells in series)? So shouldn't be that exotic.

Try shopping for lithium 12V solutions for ICE cars, which have been around forever. There just aren't that many available. They're also all super expensive. Tesla needs about 500k of them a year... and in increasing number every year. For them to want to make that switch, they'd need ideally 2 suppliers that can guarantee that volume, and it has to be worthwhile financially, offsetting some sort of operational cost.

It's probably more likely Tesla makes their own than sourcing it given their battery knowledge. But the fact that they haven't after all these years more likely suggests it's not worth it for them to pursue. That probably says a lot towards why they're still dropping in low cost 12Vs in.

 

[hcdavis3]

Try shopping for lithium 12V solutions for ICE cars, which have been around forever. There just aren't that many available. They're also all super expensive. Tesla needs about 500k of them a year... and in increasing number every year. For them to want to make that switch, they'd need ideally 2 suppliers that can guarantee that volume, and it has to be worthwhile financially, offsetting some sort of operational cost.

It's probably more likely Tesla makes their own than sourcing it given their battery knowledge. But the fact that they haven't after all these years more likely suggests it's not worth it for them to pursue. That probably says a lot towards why they're still dropping in low cost 12Vs in.

Will it fit in a Model 3?

 

[iwannam3]

So a service advisor lied to you. Shocker.

https://epc.tesla.com/#/systemGroups/47334

That's the Model 3 parts catalog for the 12v battery system.

Notice how the very first part list is the 12v battery, and it explicitly lists it available over the counter, no VIN required.



View attachment 585631

Calling the local parts department gives me a full mailbox message. Seems weird that vehicles that don't need maintenance, the parts department can't answer the phone.

 

[grmdl3]

My guess:

They re-program the BMS to only take a certain amount of power from the car, and only so often. (SNIP).

Maybe, but I wouldn't have called that a hardware solution. I'm wondering if there's a resistor or something, and whether that's on the charge circuit or the output circuit. Hopefully the former. But yeah, easier/cheaper to reprogram the BMS if that's all it takes.