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Lost on Battery/BMS wiring & config

No matter what you do with LiFePO4, the voltage curve goes exponential at the high and low, which means one cell will always end up being the weak link that looks like it "runs away" with your BMS settings using the entire 2.5V-3.65V range.
 
Looks great. It would still be helpful for those trying to help you to understand why you are getting into this empty battery situation. Too small of a battery(s) or never getting charged or ??
 
The thing about using a charger/BMS to get cells balanced is that you need to give it time to balance. A high amp charge means there may not be much time between 3.4 volts (balance start) and 3.63 volts (high voltage cutoff).

The more cycles you put the cells through (discharge below the balance current, then charge) the more opportunities the BMS will have to bring the cells into a smaller voltage differential.

Note that my definition of a cycle in the above case differs from the typical battery "cycle". It would be interesting to find out what your BMS considers a battery "cycle" since yours stands are zero cycles right now.
 
Note that my definition of a cycle in the above case differs from the typical battery "cycle". It would be interesting to find out what your BMS considers a battery "cycle" since yours stands are zero cycles right now.
Yea, I agree (with this and all you've written here).
Seeing the display of 99.1% SoC at 53.5V (3.34Vpc) I highly suspect the cells are never even close to being fully charged. My cells can sit at 3.3x Vpc for a LONG time absorbing before inching higher. I would not be surprised if the BMS does not consider reaching 53.5V a cycle, which would explain why the number of charge cycles remains at 0.

@myersfamilyhome How high do these ever get charged? Are you purposely only charging to 53.5V?
Suggest you charge to at least 3.45Vpc (55.2V).

I think you have your BMS issues worked out, moving on to your charging settings, habits and beliefs.
 
Looks great. It would still be helpful for those trying to help you to understand why you are getting into this empty battery situation. Too small of a battery(s) or never getting charged or ??
So last night I tracked the battery usage until we fell asleep. Hope this helps

Time Amps Volts VAverageUsage
-----------------------------------------------------------------
04:00P 0.0A 51.8V -------
04:30P -3.5A 51.6V -------
04:34P * Microwave 3m:40s (35A)
05:00P -02.2A 51.3V 0.50V/HR
06:00P -02.9A 51.1V 0.35V/HR
07:00P -05.4A 51.1V 0.23V/HR
09:00P -03.1A 50.9V 0.18V/HR

04:00A * BMS Shutdown everything
04:00A 00.0A 44.4V
 
Yep, what @MisterSandals said. You need to juice that charger into providing a higher state of charge. If I started the night in my RV at 35%, I would be running generator.

However, I have 560 Ah of battery capacity, so 35% of 560 Ah is still more than what you've got. The caveat to that is that I have only eight cells in 4s2p, while you have 16 cells in 16s. Not quite apples-to-apples, but I've never finished the day at less than 70% state of charge.
 
Please tell me what I'm doing wrong with my settings. Feel like I'm so lost on this. Included latest status before I swap out the cell. View attachment 123376View attachment 123377View attachment 123378
I think your cells are slightly out of balance due to having the balance start voltage set too low previously.
All the settings look good to me (or at least safe). You can of course tweak the high and low settings as others have suggested, just don't go below 2.5v or above 3.65v. I think a few cycles and they will get balanced again, and remember when you do a TOP balance, you will ALWAYS have one cell hit empty first. That's just the way it works.
 
Note that my definition of a cycle in the above case differs from the typical battery "cycle". It would be interesting to find out what your BMS considers a battery "cycle" since yours stands are zero cycles right now.

One of the reasons I dumped my Daly, never showed anything but zero cycle count.

I finally figured out that even though I selected and purchased an LFP BMS, it was set to not count as "full" until above 3.9v (or something like that). In other words, they took a BMS for a different chemistry and changed the settings to match LFP, but neglected to change how it counts cycles.

Typical Daly, the "should be good enough".
 
One of the reasons I dumped my Daly, never showed anything but zero cycle count.

I finally figured out that even though I selected and purchased an LFP BMS, it was set to not count as "full" until above 3.9v (or something like that). In other words, they took a BMS for a different chemistry and changed the settings to match LFP, but neglected to change how it counts cycles.

Typical Daly, the "should be good enough".

Ah, good to know.
 
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