Like @mstatkus above, I trickle charged with a lithium trickle charger until complete. It read about the same 14.5 volts as above. Installed (V4 not +) attached a bluetooth Lithium monitor. After 4-6 hours VCFront errors occurred. 2 "soft" errors meaning not active then a 3rd that remained active and the car stopped charging the battery. I waited and within 2 hours the charge level had already dropped to 80% and was continuing to drop. I removed the V4 and installed the factory AtlasBX and things returned to normal. So I am waiting to see if @mstatkus has a similar experience. Here his the graph:
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Longer term Ohmmu experiences?
- Thread starter Durzel
- Start date
mstatkus
Member
Overnight seemed to go ok. 99% @ 13.4V. Car was asleep all night looks like and no tesla errors.
I opened the door and battery went to charging.
As I got out of the car and shut the door it switched to discharging @3A showing 9-12hrs remaining @13.5V. I’ll keep an eye on it.
Cars back to sleep 20 mins later.
I opened the door and battery went to charging.
As I got out of the car and shut the door it switched to discharging @3A showing 9-12hrs remaining @13.5V. I’ll keep an eye on it.
Cars back to sleep 20 mins later.
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I believe your problem is the state of charge in which you are putting the battery in the system. I'm not positive about this and just take this as my best guess and best speculation but I've had none of those issues because I did not allow the battery to get anywhere near 14.5 volts. I have a version 4 plus and I used a dedicated lithium iron phosphate charger not a generic one. It terminated charging at about 13.9 volts. I tested actually to see if it would allow higher voltage by connecting and reconnecting and by the time the battery got to 14 it repeatedly activated the no charging mode. So that's one question - I'm actually not sure how you're getting past that seemingly built-in limit and I cannot explain the almost one volt disparity between my battery being charged up and what you are showing. Additionally since you are putting in a battery that is going to read as significantly higher than the float voltage of lead acid which most sources indicate is something like 13.5 to 13.6 volts, I suspect this may be convincing the operating system in the car that you have a bad battery.
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My conclusion similar. Battery voltage above car charging limit. My V4 is showing 14.1 volts on the shelf. I would need to run it down into the lower 13.x to test the thesis. I see above the 100% charging voltage is up to 14.72! I will be curious if any messages generated.
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This is interesting. Up to 14.72v. Highest I've seen. Charging when opening door normal and discharging when leaving normal. At some point car would wake itself and recharge battery. Maybe it's learning there is a lithium present? That would be way too cool but doubtful.
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mstatkus
Member
Yeah 14.72V was the highest I’ve seen; it was coming from that BMS Tool app tho. When I shut the door it went to 13.5V and discharged for a bit to 99%. It’s resting at 13.46V now.
I have a 110mi round trip to make so I’m going to toss my v3 in the trunk case it acts up.
Old Ohmmu shows 13.56V unplugged w/ max input voltage in the label @14.8V
AtlasBX 12.7V unplugged.
I did use my 12V / 8A charger on it. I’ll look at getting a LiFePo4 friendly one.
I have a 110mi round trip to make so I’m going to toss my v3 in the trunk case it acts up.
Old Ohmmu shows 13.56V unplugged w/ max input voltage in the label @14.8V
AtlasBX 12.7V unplugged.
I did use my 12V / 8A charger on it. I’ll look at getting a LiFePo4 friendly one.
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Yes your battery is showing a higher voltage than what the car charges at most of the time. There has been some speculation that occasionally the charging circuit bumps up to ~15 volts. This may be part of a so-called desulfation routine which no one has confirmed but which I speculated about being something Tesla put into the charging protocols as it may prolong the longevity of lead acid batteries and Tesla has received a lot of flack from people justifiably about the short lifespan of lead acid in their cars. This 15 plus voltage Drive would be tolerated by lead acid if it is brief but the battery management system in our batteries will not tolerate it and will disconnect. But that may be a separate set of issues from what your experiencing which may be simply that your float voltage is too high
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Correct about the disconnect but my understanding from Sean at Ohmmu is if a disconnect occurs, kit resets in about 5 minutes.
mstatkus
Member
It came with a count already up when I first got it. Want to say it was around 20. Didn’t get that detail from the Ohmmu app.
mstatkus
Member
The battery under/over temp counts via the BMS Tool. I was looking for the screenshot when I first got it but memory was the counts were already 20 or so. I googled around for what it meant but all I could find was 115F temps + which if it was AZ wouldn’t take that much to hit
So far no errors here.
I am really puzzled by the disparity in what is read as 100% voltage. At 13.5 I'm reading 100% on my Bluetooth battery monitor. This is V 4 Plus which I assume is the same as your system. I don't understand how we can have that much disparity between two ostensibly identical battery systems. I'm wondering if mine is a V4 beta. When did you get yours?
Mine is the V4 beta no plus. Got it toward the end of sending those out before they switched to the plus.
mstatkus
Member
Ok first drive 55 miles. 13.5V. 100%.
Parked for 3 hrs. Same status. Sentry mode off as I’m cleaning my moms gutters and didn’t want if going off.
Parked for 3 hrs. Same status. Sentry mode off as I’m cleaning my moms gutters and didn’t want if going off.
mstatkus
Member
..and home w/ no issue. Monitored it from time to time. Saw a 14.5V charge and 13.4-6 otherwise. Only ranged 99-100%. Charging the car up from 32%. Car did 245Wh so that’s cool.
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So no issues but there was at first. Wonder why? Maybe it is learning. Maybe I’ll try installing my V4 basic tomorrow and see what happens. Which software running?
mstatkus
Member
I had one thing that made me feel like this needed another try; I felt like my negative cutoff switch I installed may had caused a weak ground issue. It’s installed now w/o it. I was using it to save me from removing my HEPA filter to just reset the battery.
Car is still in 2022.28.2. No notification yet to update.
So today I reinstalled a V4 (not V4 +) battery at 11:00 EST. Battery voltage prior to install was 14.12v. So below the normal charging voltage. Once installed, the V4 began its 4-6 hour charge cycle (occurs every time a battery is in stalled). Charging voltage was 14.37 volts and holding steady. No messages after installation. I will check back later today to see if any messages occurred. I'm running FSDBeta 2022.20.18.
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mstatkus
Member
So far no incidents for me. I’ll be away for a few days. I did see the car topped off charge this AM but no messages so far.
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