Lithium battery capacity detection circuit diagram principle

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Overview:
A netizen wants to know the capacity of each section of the ten-cell battery on hand, and has designed a capacity detection circuit. Many netizens who have targeted this circuit have also brainstormed and given their own design ideas. Let’s take a look at this. The design prototypes given by netizens and the extended design of other netizens, what better ideas do you have for such lithium battery capacity detection circuits? Welcome everyone to discuss.

There are 10 18650 batteries on hand. I want to know how much battery capacity each battery has, so I made a simple capacity detection circuit. The circuit diagram is as follows:

TL431 limits the voltage on the 9 ohm resistor to no more than 2.5V, which is equivalent to limiting the discharge current of the lithium battery to less than 277mA. The lithium battery will discharge at a constant current of 277. When the current is discharged and the current is less than 277 ohms, the voltage on the 9 ohm resistor drops, and the LED will illuminate. The function of the 0.1uF capacitor is to prevent the TL431 from generating self-oscillation. Record the start discharge time and the start time of the light-emitting diode, and multiply by 277mA to know the capacity of the lithium battery. The following is a good physical map:

Yellow is a small capacitor, TL431 is blocked by this capacitor, the leftmost is a 9 ohm resistor, it will be hot, the head can not be small.

The following is the full picture:

The 5V voltage is taken from the phone charger.
(Please read the PDF for details)