Sean sent me V29 firmware to replace the V65 I used. Heating appears ti have returned to normal. No idea what is different in each release. Will see this weekend if it improves. So far it is OK.
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Longer term Ohmmu experiences?
- Thread starter Durzel
- Start date
The Ohmmu site now has V29 firmware as the current version for the V4+. I have a V4+ heated and it has been working well since I switched fro V65 to V29. Make sure after installing V29 you install the vehicle configurations software (i.e. Model 3).
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mstatkus
Member
Cool thanks. Adding link here Ohmmu | BMS Firmware Updates - Google Drive
Occurred to me to the way this works someone could flash your battery remotely too heh.
I'm still trying to figure out if that bin file flashes the bluetooth module or the actual BMS itself. JBD doesn't have much on there process and most of it is in Chinese.
Occurred to me to the way this works someone could flash your battery remotely too heh.
I'm still trying to figure out if that bin file flashes the bluetooth module or the actual BMS itself. JBD doesn't have much on there process and most of it is in Chinese.
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mstatkus
Member
Yeah that works.. was able to compare the serial 16930001 to the right PDF.
Looks like heating function in charging state is turned on at 32F and off at off at 41F. The heating (pad) not connected as mine is older.
Notes on freezing temps -
4.5.2. Charge and discharge low temperature protection and recovery
When charging and discharging, the NTC detects that the temperature of the cell surface is lower than the set low-temperature protection temperature, and the management system enters the low-temperature protection state.
In this state, the charging or discharging MOSFET is turned off, and the battery pack cannot be charged or discharged in this state.
When the temperature of the cell surface rises to the low temperature recovery set value, the management system recovers from the low temperature state and restarts charging and discharging.
On recovery:
Looks like I should be able to use there UART Bluetooth module to flash the bin again as my onboard Bluetooth is unresponsive. They also reference a UART Communication box for a PC and a RS485. Least I'll see if this works. Good DIY fun either way. No PC here so I'll see if the OTA works via that method.
On the V4+H I notice the battery temperature about 13F warmer than the non-heated V4+ while the car is asleep. Upon preconditioning prior to departure the OAT was mid 40's along with garage temperature. The Battery warmed to 60. Now that may be in part to the inductive heating a 2020 M3 has since no heat pump. Since I have AWD the battery sits above the motor.
V29 continues to work well. Parked outside this morning at 30F. 3 Hours later is was 37F no war rings or messages and the battery was 50F while car asleep. Warning to 60F with OAT of 44F. Continues to be 13F warmer than non-heated V4+.
V29 continues to work normally. No errors no warnings no messages. Using a V4+ Heated.
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All I can say is so far it has been working fine. I have had is below freezing and the battery maintained a temperature in the upper 40's to low 50'sF. I have yet to run it at outside temperatures below about 28F. But it appears to be working as advertised. My backup battery (should this one have issues) is a DiehardEV which also worked just fine. I prefer the Ohmmu as it is easier to monitor with the app and the fact that both configuration and firmware can be updated should there be any changes in Tesla makes it attractive to me. I will continue to post progress during the winter months.
Additional GOOD information this morning. Parked outside at 23F. Came out again 2 hours later temperature 28F. Battery temperature 59.4F. No warnings or messages in Notifications or Service alerts in Service Mode. Car charging the 12 volt initially at 14.9V (probably doing a battery test as if Lead Acid). All is well with V29 on the V4+ Heated.
If anyone else has a V4+ Heated and updated firmware to V29 please post your cold weather observations.
If anyone else has a V4+ Heated and updated firmware to V29 please post your cold weather observations.
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I've been running on V4 (no battery heater) for a few months now in my Model 3 + FSD train software, and it's held up just fine. We don't really get below freezing temps in Silicon Valley though... which would probably explain why I haven't seen any 12V issues so far.
mstatkus
Member
So 14 degrees with the lead acid. Barely could open my power frunk. It could not close it. I had to reset the latch and push it down manually. In similar fashion my trunk so slow it sounded like slow motion. But did not open all the way.
So I had to ponder if this is a sign the powered struts and motors can’t work or if the battery just can’t deliver the juice.
So I had to ponder if this is a sign the powered struts and motors can’t work or if the battery just can’t deliver the juice.
From volts.ca "Lead-acid batteries lose capacity in normal to cold weather by about 20% and in temperatures as low as -22°F(-30C) by about 50%." Also this "Lead-acid batteries operate at 70–80% of their rated capacity at temperatures below 32°F, significantly reducing their efficiency and useful capacity. On the other hand, Lithium batteries can function with relatively little loss at the same temperature, delivering 95–98% of their capacity."
mstatkus
Member
Sounds like I got this JBA bluetooth module at the mailbox so I’ll try to pick it up tomorrow and see if I can recover my v4+.
mstatkus
Member
I think it’s toast. Bluetooth UART just lets you connect but the underlying bits don’t respond or take a flash.
JBA routes you to Ohmmu. I didn’t get a response.
Also interesting anyone with that software could basically flash your battery in the wild.
JBA routes you to Ohmmu. I didn’t get a response.
Also interesting anyone with that software could basically flash your battery in the wild.
Well, I joined the club since these finally seem to be making some progress. Let's see what happens. For me, I'm supporting local since Ohmuu is in AZ like me. I charged mine from 30% to full using an external charger before putting into the car, and so far, so good. I have no idea how to update firmware or what to monitor quite yet aside from just not seeing error codes in the car, but hopefully this can make a good long term no fuss replacement for the life of the car. One thing I can say is that I love the bluetooth connectivity to the app and that the app is no-fuss. Just simply download the app (no BS creating an account) and connect it to the bluetooth in the battery. The app took all of 2 seconds to get it up and running and it's a clean no frills interface.
Attachments
Do this step to configure the battery for your model car. Be close to vehicle within bluetooth range. It will take a few minutes so be patient.
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