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Hello

I have a total of 5- Tesla Model S Lithium Ion 18650 Battery Modules 6S 5.3kWh wired in series monitored by Thunderstruck's Dilithium Design BMS

Needing setting info for the following

Cell Balancing Voltage Cutoff-
Cell Discharge Balancing Voltage Minimum-
Thermistor Max Temperature-

And a conformation on the settings I have already done.

High Voltage Cutoff 4.15V Cell
Low Voltage Cutoff 3.3V Cell

Any Info will be appreciated!!
Thanks!!
 

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I would find out what values Tesla uses and aim for those. I'm using Leaf modules, but had similar questions:

https://www.diyelectriccar.com/forums/showthread.php?t=202151

I decided on 4.1v being "full" and 3.6v being "empty". I have my balancing voltages set for 10mV under, but my charger is a very slow 5A to begin with. You might need a larger window to ensure balancing. It might require some real-world testing and tweaking.

Maybe start conservative and see how it goes.
 

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Maybe start conservative and see how it goes.
+1, i agree.

Get a good feeling for the calibration of your voltmeter to measure correctly. It's easy to raise a level later, but overcharging can not be undone. E.g. 4.15 is really close to the absolute upper limit and the least inaccuracy in the system could send you over the top. So set it at 4.000 and see how well it meets this and how good your meter is at measuring and verifying this. Then you can increase the level and limit it you feel that you need higher.
 

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Is the BMS actually controlling the charge cycle or is it just a failsafe backstop?

Isn't that a "first cell that gets to" HVC?
 

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Start balance should be low V /early enough so they regularly get all balanced before you want to stop charging normally.
 

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It depends on how your charger is setup to communicate with your BMS.

For my CAN setup, the BMS does nothing more than send messages to the charger, such as "HVC reached". It's up to the charger to know to stop charging or reduce current based on these messages.
 

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A safer design is one where the charger only runs as ling as it's getting OK signals, say every 15sec.

So early stop if the BMS fails.

And the BMS HVC is a backstop for if the charger fails to stop.
 
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