-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Longer term Ohmmu experiences?
- Thread starter Durzel
- Start date
I'm still puzzled as hell as to why your float voltage is so much higher than mine. I suspect that that was one of the things that Ohmmu somehow corrected or modified in V4 Plus. I had always assumed that the problem was BMS disconnecting if it detected too high of a charging voltage drive. All of this makes me think that the problem was somewhere else - the system reads the float voltage as too high and rejects the battery. Or maybe it's some combination or add mixture of those problems. In any case my system will not allow my float voltage to get above 14 volts. If I even try it disconnects the battery
Last edited:
My charge voltage regardless of Ohmmu or lead acid is about 14.4. It will then float at about 13.3 for a bit before stopping charge ( normal with the most recent update -FSDBeta). Previous FSDBeta world charge spike then stop with no float. I will know in a few hours how this latest update will fully respond. The non-FSD software may have a different charge profile. I will add todays graph profile later today.
I would like to ask folks with Ohmmu experience what they would suggest for my situation...
I have a 2018 Model 3 Performance and purchased/installed an Ohmmu battery last October. Partly to head off a failure of the original 12v battery, and partly to get more life without worrying about a replacement lead-acid 12v battery. I'm in the fsd beta, so my software path is slightly different from the general rank and file. Everything had been working fine for about a year.
I have been on a 3,000 mile road trip. Halfway through the trip, a software version became available (2022.20.18), so I connected to wifi and downloaded it. Within about 6 or 8 hours, I received alerts for vc_front_a182, a192 and a402. I read the knowledge base article on Ohmmu's website and sent them a note. They responded back with a scripted message that essentially had the same information in the website article.
It was about time to come back home, and I was nervous. I didn't have the tools to do a reset on the battery, but I didn't have another software update waiting to install anyways, so I decided to tough it out and try to get home. All the way home, I didn't let the car go to sleep. I left it in camp mode all the time when not driving (I had no idea whether this would be successful or work). I figured even though Ohmmu said the battery would most likely not die, I didn't want to take any chances since we had to drive in some pretty remote territory to get back home. It seemed to work okay with camp mode, etc. although we lost USB port functionality (can't charge our phones) and it wouldn't pre-heat before charging (or at least display the message). It also required extra charging since it burned up more energy at night, and required some additional planning. My SO wasn't too happy about the whole thing.
So now what? After driving the car somewhat crippled back home for over 1,500 miles and having to worry that it may conk out at any moment if I'm not careful with the camp mode, I have lost faith in the Ohmmu battery product. I'm tempted to buy a replacement lead-acid replacement from Tesla and try to do a pro-rated return to Ohmmu or get an upgraded replacement from Ohmmu that I can just sell to cash out (just sent them a note to see if either of these two ideas are viable).
Any other ideas or suggestions? Thanks, I appreciate it....
I have a 2018 Model 3 Performance and purchased/installed an Ohmmu battery last October. Partly to head off a failure of the original 12v battery, and partly to get more life without worrying about a replacement lead-acid 12v battery. I'm in the fsd beta, so my software path is slightly different from the general rank and file. Everything had been working fine for about a year.
I have been on a 3,000 mile road trip. Halfway through the trip, a software version became available (2022.20.18), so I connected to wifi and downloaded it. Within about 6 or 8 hours, I received alerts for vc_front_a182, a192 and a402. I read the knowledge base article on Ohmmu's website and sent them a note. They responded back with a scripted message that essentially had the same information in the website article.
It was about time to come back home, and I was nervous. I didn't have the tools to do a reset on the battery, but I didn't have another software update waiting to install anyways, so I decided to tough it out and try to get home. All the way home, I didn't let the car go to sleep. I left it in camp mode all the time when not driving (I had no idea whether this would be successful or work). I figured even though Ohmmu said the battery would most likely not die, I didn't want to take any chances since we had to drive in some pretty remote territory to get back home. It seemed to work okay with camp mode, etc. although we lost USB port functionality (can't charge our phones) and it wouldn't pre-heat before charging (or at least display the message). It also required extra charging since it burned up more energy at night, and required some additional planning. My SO wasn't too happy about the whole thing.
So now what? After driving the car somewhat crippled back home for over 1,500 miles and having to worry that it may conk out at any moment if I'm not careful with the camp mode, I have lost faith in the Ohmmu battery product. I'm tempted to buy a replacement lead-acid replacement from Tesla and try to do a pro-rated return to Ohmmu or get an upgraded replacement from Ohmmu that I can just sell to cash out (just sent them a note to see if either of these two ideas are viable).
Any other ideas or suggestions? Thanks, I appreciate it....
Last edited:
Currently, several are testing the V4+ battery from Ohmmu (the + has Bluetooth so you can monitor the battery). I have the factory AtlasBX on the shelf, a DiehardEV battery (designed for the M3 and is AGM), and the V4 (non +). I decided to try reinstalling the V4 since installing 2022.20.18. Having monitored charging behavior for a while with those add-on modules I wanted to see with version 2022.20.18 if any errors would occur. It's only been 24 hours but no passive or active VCFront messages. I took a different approach. When I originally installed the V4 on the previous FSDBeta, I got a normal charge of about 14.4 volts for 6 hours then 2 VCFronts followed by a third that stayed active and locked out charging. So the V4 ran down to about 80% where I removed it and put it on the shelf. That was July. The DiehardEV worked just fine no messages or issues. Normal charging behavior on any battery install is the car goes i to charge for 6 hours then float (that is recent FSD priors didn't float), then resting. I don't have 24 hours of V4 data as I had to swap out the bluetooth module BUT never got any warnings and check resting voltage this morning of the V4 at 13.34 volts. Similar to others in this thread. One contributor has noted Tesla has changed charging profiles dozens of times over the years basically as trial and error. A 100% charged V4 (using a trickle charger) comes in at 14.4 which is about the cars charging limit (FSDBeta). I have seen higher limits on the Non-FSD branch up to 14.7. So my approach on the new attempt with new software was to install a partially run down V4 battery. It tested at 14.12 prior to install. Charging went to 14.4 as expected. Today, it showed 13.34 when asleep which is similar to others. Wake it up and charging at 14.45 or so. Doing a battery swap is not difficult and if proper steps are done, no post install warnings will be present. I would suggest one of two approaches - 1. see if you can get a V4+ which is supposed to be distributing at the end of the month (caution while a great battery and bluetooth monitor will allow resets in the future the warranty is void if Tesla changes software to block compatibility again), or 2. Get a DiehardEV battery (supposed to last 30% longer than regular AGM and is warranted for 3 years). The factory AtlasBX is just a basic lead acid battery (but high density as it is 625 CCA and 45 AH). The Diehard is 41 Ah and 410 CCA but as I said is made by Clarios, distributed nationally by Advance Auto and I would think Clarios spoke to Tesla in manufacturing process for compatibility. If you go the Diehard route, then in 2-3 years change it for the Ohmmu. Like you, I want a battery like the new cars where I can put it in and forget about it for years. If I continue without errors, I may see about swapping for the V4+ with really good monitoring.
mstatkus
Member
So my wife hit the widget in her phone accidentally Monday morning and opened the trunk for 24hrs. I just spotted it after logging into my garage camera lol. So throwing a little extra test into mine while I’m away.
israndy
Supercharger Hunter
The downside of multiple Teslas, I have been on roadtrips with friends who want to get into their trunk and open another family members trunk 1000 miles away. Always fun. It prompts you "Are you sure?" but it doesn't say "You know this car is not w/ in your line of sight".
So far, my V4 Ohmmu (not V4+) seems to be working OK with FSDBeta revision 2022.20.18. The battery started out normal with a 6 hour charge at about 14.4v. Then reduced to about 13.3v Periodic charging up at 14.4 the settling down to 13.3. The I installed, it was not fully charged so the voltage was below the charging voltage of the software. No VCFront messages or any messages. It also appears from others with V4+ that those using the 2022.28.x branch are seeing similar results but with slightly higher charging voltages.
Nice! I've not had so much as a peep out of the system since I put the V4 plus version in. No alerts no warnings no nothing all is Quiet on the Western (12v) front. Just the way we like it!
mstatkus
Member
I came home and found *a few errors. Battery was down to 10%. Lead acid is back in. In my haste the negative adaptor fell into the void so I’ll have to fish that out later.
Well send the information to Ohmmu. I was hoping the most recent updates would prevent this. No idea why all of a sudden this happens. So far mine has been hanging in but I a also using FSDBeta 2022.20.18 and the charging profiles may be different. it's almost like the app even though its says enable charging is actually off.
Last edited:
mstatkus
Member
Yeah I’m still on 2022.28.2 but can’t get updates if this keeps happening.
I’ll pass it back to ohmmu. Putting the battery on a LiFePo4 charger now. Even handy to carry in the trunk if the lead acid failed at 8lbs or so heh.
Ah this shim isn’t magnetic. This will be fun. JIS to SAE looks like. $6 might be cheaper than trying to find it.
I’ll pass it back to ohmmu. Putting the battery on a LiFePo4 charger now. Even handy to carry in the trunk if the lead acid failed at 8lbs or so heh.
Ah this shim isn’t magnetic. This will be fun. JIS to SAE looks like. $6 might be cheaper than trying to find it.
Last edited:
Damn I have to confess that's troubling. It looks like the same process or at least a similar one to earlier versions of the battery. Something appears to break the handshaking and charging protocol, then the battery drains over several days then you get the dreaded VC front service code. There must be some explanation for this? What has been your general float voltage when you've checked it? Mine is never above 13.6. Mostly it's 13.4 13.3 or 13.5. It looks like from the graphic that you pasted that your float voltage might be something like 14.2. I'm still wondering if that's just too high. It certainly is enough higher compared to lead acid that the system might see the battery as a bad actor. I'm really wondering if there are in fact actual BMS differences between what are labeled as identical V4 Plus batteries. My BMS would not allow me to charge over 14 volts. It disconnected when I tried. That clearly is not happening with some other version 4 plus batteries with the Bluetooth monitoring systems. So the mystery of all this only deepens.
Last edited:
mstatkus
Member
Agreed. Suspect it hits a high voltage. Normally 13.3-13.6. But I was seeing 14.72 when it was applying some pulsing it performs. We really just need a LiFePo4 option vs the lead acid profile.
I’m going to get creative and use my Blink cam to find my shim down in the void haha.
When I lost my terminal shim, I had to remove the frunk liner (not the bad) and it was sitting there. I had the same question if Ohmmu issued several test batteries adjusted differently. Lets us know if they answer your inquiries.
Wondering why my system does not appear to show that pulsing. I'm pretty confident that you could kludge a workaround where you take the battery charge it to 13.6 put it back in do a reset, and it would probably work fine - for a while. But yeah that's too much work.
Not looking forward to fighting with Tesla about the lead acid failure in the powerwalls. They really don't know what they're doing with sealed lead acid batteries
Not looking forward to fighting with Tesla about the lead acid failure in the powerwalls. They really don't know what they're doing with sealed lead acid batteries
mstatkus
Member
Yeah I'm tempted to shut down the charge around 85% so I can let the car finish it. I think what I'l do though is fish out my shim, let the lead acid run so I can catch the last software update then resume testing. This new charger is only pushing like 1.5A around 13.6V right now after 9hrs. It's at 82%.
Pulsing I saw was a 0.42A push about ever 2-3 seconds while the battery was at 100% At 14.72V.
Interesting enough since I was in a meeting it made it to 87% and the charger had stopped saying it was FULL.
Think I found it. Might be easier to drop the skid plate.
Last edited:
mstatkus
Member
Similar threads
