Discrete Large Lithium Battery Control

The cells I am writing about are 3.7 volts. I guess they figure that if a voltage module goes offline because of a bad cell then retaining the remaining batteries of that module is a waste of time.

My concept is to maintain each cell much more carefully and not allow it to stray too far from optimum charging quality.

Unless the lithium came from a different universe an optimum routine cannot help but extend cell life thus, module and battery life. This is a universal rule in electro chemical applications.

If trying to argue the point remember decoupling alternator pulleys that offer .00000012 miles per gallon gain and ECU voltage regulators that hunt all over the map and new vehicle ECU analysis of alternator/battery parameters. All combined in the same bucket they're not worth half a honk of snot.

OEM engineers continue to lose focus in order to justify their salary.

Individual monitoring and maintenance is what I give to my two volt Rolls cells. This does not differ in concept from Word War II submarine 380 volt fore and aft battery maintenance and control.

Discrete amperage monitoring is useless re: Kirchoff's Law.

i'm PRE-neophyte all i have been doing is reading, watching videos, looking at wiring drawings (no hands on)

it seems everything i have seen regarding large scale
goes to 'cell groups', cells in parallel packs, or cells in series packs
treated as one larger cell
for 12v, 3-4 cells arranged series depending on chemistry, and parallel the needed number of packs needed for the 'pack size'
some use individual BMS units on each 12v group wired to each cell
it is charged with a 14.x charger, not with a 5v charger

some parallel a number of cells then series them for 12v ? bank voltage
the BMS goes to each group of parallel cells, but not too each individual cell
they also use a 14.x bank charger not 5v

i have not seen anything using a 5v charger running to BMS or cells
to charge a bank wired for higher output voltage 12, 24v, etc

i saw a video discussion on tesla batteries
the cells were connected with 'fuse wire' to a buss bars
no individual BMS per cell
buss bars arranged the cells in large parallel packs that are series
for high voltage
if a cell goes bad, takes too much charge power or too much output
it takes out the fuse and that single cell goes off line
these parallel packs are very large so loosing a few cells will not cause a noticeable affect on performance
loose to many and you a 'alert' regarding battery capacity and service

there is a BMS of some sort, but i 'think' it deals with each large parallel group as one large cell

BMS is concerned with cell group voltage and total power out or total input needed , which indicates too many 'individual' cells are offline

To a pessimist a glass is half empty
To an optimist a glass is half full

To an engineer, the glass is twice as big as it needs to be.

A large capacity Battery control and charging circuit cannot be anywhere near the price of these discrete components. The design has one weakness. It cannot determine when the battery is full - then shut off automatically.

So individual cell monitoring is mandatory. A bit of experience and a wind-up timer should fill the bill in this area. The Meanwell power supply is switchable 120/240 so larger 5 volt Meanwell power supplies can support battery banks rated in the thousands of amp hours.

I see MEX has been thinking on things again..