Ohmmu 12V Battery Feedback

[Perscitus]

Ohmmu has shared their refund and replacement warranty info in the other thread (a few pages back from latest).

In a nutshell - no refunds unless original purchase was recent (very recent). Replacements have their own warranty which notibly does not extend beyond the warranty of the original purchase.

v4+ does not solve the issue/s with Teslas modified LVB diagnostics and VCFront error triggering logic introduced with 2021.36.x and still present in 2022.40.x

It is highly unlikely that Tesla will do anything about this (just like not allowing for seamless retrofits of active-matrix headlights, global tailights) since the lead-acid equipped 3s/Ys are considered 'legacy' products and Vision-only HW3.5 + Ryzen + 15.5V LFP LVBs are the current single-stack target.

 

[Stanwood Steve]

I feel I need to weigh in again given that I'd previously indicated no issues with the Ohmmu battery installation on my 2018 Model 3P about two years ago. It had been completely trouble free. I was recently out of the country for a couple weeks and left my car plugged into the wall charger with max charge at 70%. Everything should have been fine, but when I returned I received the dreaded alerts about a low battery voltage situation. I have an Ancel battery monitor on it, and it was only showing 12.4 volts so clearly it had not been trickle charging while I was gone. I drove to Tesla and picked up a new 12v OEM battery and installed it, and stuck the Ohmmu on a battery tender to see if it would charge back up to 13.5 volts. It did, but took about 36 hours to get there. I have sent Ohmmu a message on this, but no word back from them yet. To be fair, it is a holiday week. Anyway, no longer can I report no issues with the Ohmmu battery. Back to the OEM lead acid battery, I guess.

 

[Flybyglass]

I have a V4+ coming. Sent a note to Sean to see if any firmware changes to know about. I will test an AntiGravity Lithium Battery Tracker to see if it interferes with the V4+ Bluetooth and if not, I should be able to track charging cycles and get an early warning is an MOS Lock has occurred. I still have a Tesla battery on the shelf and a DiehardEV B24L AGM I am currently using (no issues) as backup if the V4+ goes wonky.

 

[Flybyglass]

V4+ is now out on the Ohmmu site. The production V4+ has different firmware and slight adjustments than the V4+ beta test batteries. Major advantage, resettable without tools or disconnecting main battery if necessary. All can be done from the driver seat.

 

[Benjamin Brooks]

V4+ is now out on the Ohmmu site. The production V4+ has different firmware and slight adjustments than the V4+ beta test batteries. Major advantage, resettable without tools or disconnecting main battery if necessary. All can be done from the driver seat.

So I'm supposedly on the warranty replacement list for the older Model 3 battery that constantly has issues with Tesla's latest firmware... anyone get notifications about these shipping out for warranty replacements yet?

 

[Flybyglass]

So I'm supposedly on the warranty replacement list for the older Model 3 battery that constantly has issues with Tesla's latest firmware... anyone get notifications about these shipping out for warranty replacements yet?

If available on the web site then probably available for warranty replacements. Send a note.

 

[Perscitus]

v4+ beta or non-beta does not solve the inherent issues (flawed logic with no end user config overrides) present in Tesla firmwares since 2021.36.x up until 2022. 48.x etc.

So for anyone hoping this is solved, its not and might never be now that this setup is considered legacy, depricated by the 15.5V LVB setup.

Once the errors throw and until you clear them, the car will drain the LVB like there is no tomorrow, killing a nearly full Ohmmu LFB LVB within less than 12-24hrs.

 

[Flybyglass]

v4+ beta or non-beta does not solve the inherent issues (flawed logic with no end user config overrides) present in Tesla firmwares since 2021.36.x up until 2022. 48.x etc.

So for anyone hoping this is solved, its not and might never be now that this setup is considered legacy, depricated by the 15.5V LVB setup.

Once the errors throw and until you clear them, the car will drain the LVB like there is no tomorrow, killing a nearly full Ohmmu LFB LVB within less than 12-24hrs.

Maybe true. I’ll still try it and monitor with an additional external module to see what happens. They would not have made firmware changes and adjustments for nothing. I have my Tesla 12v and a DiehardEV battery ready if needed.

 

[xmodem240]

So i recently got my new v4+ battery and tried it out this weekend with tons of issues. First issue was it seems for me at least that the bluetooth part of the bms was causing interference with my phone connecting to the car. I could not get it to pair and connection always failed. I also have the sexy buttons in my car which uses a bluetooth adapter to the car to get its info and such and it was also having issues connecting.

Second issue was, the car would not goto sleep after installing the battery. I did take into account that when you swap the battery it takes 6 hours for the car to do its checks and such. But i woke up sunday morning with the car still awake and in the death spiral drain of the 12v.

Third issue was the ohmmu app was showing the battery getting charging overvoltage and mos lockin a few times. Then finally on sunday the car gave me the infamous vcfront errors and started its death spiral to draining the 12v battery to zero. So i just said f'it and removed the battery and put back in the stock battery. After that, no issues with bluetooth or car errors. So i guess i wait for maybe an update to the firmware of the battery for trying my next attempt. Seems to me tesla immediately knows when something other then a lead acid battery is installed now, the error shows up almost immediately now vs the older models of the ohmmu where it would takes months for the error to occur. I would have just done the reset to the battery now that its bluetooth, but the interference with my phone made that unusable to me at least.

 

[Flybyglass]

So i recently got my new v4+ battery and tried it out this weekend with tons of issues. First issue was it seems for me at least that the bluetooth part of the bms was causing interference with my phone connecting to the car. I could not get it to pair and connection always failed. I also have the sexy buttons in my car which uses a bluetooth adapter to the car to get its info and such and it was also having issues connecting.

Second issue was, the car would not goto sleep after installing the battery. I did take into account that when you swap the battery it takes 6 hours for the car to do its checks and such. But i woke up sunday morning with the car still awake and in the death spiral drain of the 12v.

Third issue was the ohmmu app was showing the battery getting charging overvoltage and mos lockin a few times. Then finally on sunday the car gave me the infamous vcfront errors and started its death spiral to draining the 12v battery to zero. So i just said f'it and removed the battery and put back in the stock battery. After that, no issues with bluetooth or car errors. So i guess i wait for maybe an update to the firmware of the battery for trying my next attempt. Seems to me tesla immediately knows when something other then a lead acid battery is installed now, the error shows up almost immediately now vs the older models of the ohmmu where it would takes months for the error to occur. I would have just done the reset to the battery now that its bluetooth, but the interference with my phone made that unusable to me at least.

The V4+ I installed was just shipped last week and has some adjustments to firmware. I noticed on the outside it has a max voltage of 14.85v. I think the earlier one had 14.7v. (I asked Sean and they have been tested to in excess of 15 volts. My car slept first night and Ohmu dropped to 99% (again Sean said it takes several charge discharge cycles for the percentage to be accurate). I woke the car this morning and it is charging 7 amps input and 14.41v showing 100%. No bluetooth interference but all I have is IPhone/Watch and cars bluetooth. No other external devices. I decided NOT to install a battery monitor to prevent 2 bluetooth emissions from one location. I thought the module and battery could interfere.

 

[xmodem240]

The V4+ I installed was just shipped last week and has some adjustments to firmware. I noticed on the outside it has a max voltage of 14.85v. I think the earlier one had 14.7v. (I asked Sean and they have been tested to in excess of 15 volts. My car slept first night and Ohmu dropped to 99% (again Sean said it takes several charge discharge cycles for the percentage to be accurate). I woke the car this morning and it is charging 7 amps input and 14.41v showing 100%. No bluetooth interference but all I have is IPhone/Watch and cars bluetooth. No other external devices. I decided NOT to install a battery monitor to prevent 2 bluetooth emissions from one location. I thought the module and battery could interfere.

Have not looked on my battery to see what its max voltage is.

As for the bluetooth, im going to bring home my spectrum analyzer tonight and see how much signal is coming out of the battery. Ive never seen bluetooth interfere with bluetooth before but there is always a first.

 

[Perscitus]

Keep us posted on how long it lasts in this error free state.... in my case it took almost a month for the VCFront christmas tree to show up, buy showup it did.

Ohmmu app and support hub are not reporting any firmware updates for the v4+s available for download yet. Did Sean say anything about ETA (he stopped replying to me on a few threads in November and has been MIA since).

Any v4+ has the bluetooth active and broadcasting 24/7 whether its connected to or not. So not using the app and/or pairing with the phone, is only half yhe equation.

Also sorry to hear about xmodem (zmodem, kermit?) experience. My v4+ has been on the shelf collecting dust for a few months now too. Sad.

 

[Benjamin Brooks]

Keep us posted on how long it lasts in this error free state.... in my case it took almost a month for the VCFront christmas tree to show up, buy showup it did.

Ohmmu app and support hub are not reporting any firmware updates for the v4+s available for download yet. Did Sean say anything about ETA (he stopped replying to me on a few threads in November and has been MIA since).

Any v4+ has the bluetooth active and broadcasting 24/7 whether its connected to or not. So not using the app and/or pairing with the phone, is only half yhe equation.

Also sorry to hear about xmodem (zmodem, kermit?) experience. My v4+ has been on the shelf collecting dust for a few months now too. Sad.

Anyone with 4+ on their Model 3 and still having issues regularly? I'm kinda waiting until their BT app supports an automated BMU reset for the car, or until newer firmware is released...

 

[dfwatt]

Anyone with 4+ on their Model 3 and still having issues regularly? I'm kinda waiting until their BT app supports an automated BMU reset for the car, or until newer firmware is released...

I do not believe that a totally battery Centric app is capable of doing a genuine or full 12 volt system reset. There are reports that if you put the car in tow mode it disconnects the dc/dc contactors. But I believe you're going to have to do that in any case. It's not a big deal though because it's really 10 seconds of work to lift the rear seat and latch and then pull up on the connector until the contactors tell you they're off. Then you can shut down the battery through the app and you're good in 2 minutes. If you're waiting for Tesla firmware to stop abusing the lfp battery good luck.

 

[Flybyglass]

Anyone with 4+ on their Model 3 and still having issues regularly? I'm kinda waiting until their BT app supports an automated BMU reset for the car, or until newer firmware is released...

I've had my V4+ installed now for almost 4 weeks no issues including a normal software update (to the car). Ohmmu meet with the app team and thinks they will have an updated app with battery software revision and data collection ability by end of Feb.

 

[xmodem240]

So installed the v4+ back into my car yesterday and it seems mostly fine but the car doesnt like to goto sleep after driving. Car will goto sleep after its done charging but not when after driving. Just sits and idles for hours. Thoughts?

 

[gearchruncher]

It's been my experience that when putting a new battery in the car, it can go through a charge and test cycle for that battery that takes a couple days and keeps the car awake.
And of course, depending on how you're checking it being awake, you may be the one waking it up.

 

[James Cole]

do you guys happen to know the specs of the ohmmu 4+? does it have more power/capacity?

Thanks
JC

 

[Flybyglass]

So installed the v4+ back into my car yesterday and it seems mostly fine but the car doesnt like to goto sleep after driving. Car will goto sleep after its done charging but not when after driving. Just sits and idles for hours. Thoughts?

The only time I noted it staying awake was after initial installation for about 6 hours. Then sleep wake cycles normal. You can monitor the battery via Bluetooth without waking the car to see any activity (charging or discharging). Also, perhaps a reboot to see if normal cycles return.

 

[Flybyglass]

So installed the v4+ back into my car yesterday and it seems mostly fine but the car doesnt like to goto sleep after driving. Car will goto sleep after its done charging but not when after driving. Just sits and idles for hours. Thoughts?

Suggestion try completely closing the tesla app. I have found sometimes if the app in not closed the car stays awake. In IOS when closed I swipe up to remove then I get a popup message saying keep open for best performance. then I know its complete closed.