New lifepo4 battery bank

[ClassicCrazy]

So I am updating on the performance of my CALB lifepo4  batteries and 123smart BMS.

Batteries seems to be performing well .None or minute differences in voltages at different SOC.Basically like new.

123 Smart BMS however,has been greatly disappointing.
After measuring voltages at different socs and at rest on many occasions I have concluded that this BMS is not accurate in measuring voltages.Readings are all over the place .I even borrowed a fluke just to ensure my radio shack DMM wasn't giving incorrect readings.Turns out my radio shack is as accurate as a fluke and even a klein tool DMM.

This, I have been noticing for nearly a year ,yet I didn't remove it because it was still giving so level of monitoring.
Finally , for two days one of the the boards kept reading a high voltage shutting down charge to the system.Upon removal and verifying on a different cell it was found that the board was defective .Because of this I have now choose to bottom balance and use the SOC setting on the classic to disconnect the inverter.

Bottom line the 123 smart BMS is not worth the money($500+) US.
I support again when I said I wish there was a wb Sr. that has all the features of the wbjr but with individual cell voltage monitoring and temperature.
Calibration setting would be nice too.

123 smart BMS lack this feature .Board cannot be calibrated.

There are some other less expensive BMS on the market now  - and also a different technology that Ross talked about which balances cells. Sorry to hear your BMS failed.
I tried doing bottom balancing on my Calbs following advice by someone else doing that. I had a few things mess up - might have been my fault but I didn't have any low voltage disconnect. I think the Classic itself took my cells down too low once because it will run to a very low voltage just to be on . So you probably want something that will cut off everything  like maybe contactor in battery line .  Wish I had one then - and also wish I knew what I was doing ! ha ha but they were kind of an experiment .
Check out this store on Aliexpress - this is just one of the many configerations they have listed
I bought a little bms from them and it arrived pretty quickly
https://www.aliexpress.com/item/32888385718.html?storeId=4165007&spm=2114.12010612.8148356.1.388f37feRnpYy4
I have also seen some BMS mentioned in ebike forums that you can connect to via bluetooth via smartphone and the app will show you each individual cell data - not sure if there are those available for bigger size packs like you want but worth checking into .

Larry

[RossW]

I wish there was a wb Sr. that has all the features of the wbjr but with individual cell voltage monitoring and temperature.
Calibration setting would be nice too.

123 smart BMS lack this feature .Board cannot be calibrated.

http://support.rossw.net/batterymonitor/ are monitoring only of voltage (and optionally temperature) of each cell and cascadable for basically any practical voltage bank or chemistry. Can be (re)calibrated in-situ if its ever required.