Same here!!
Cells are to be used during charge to maximal 4.2 v
That is, at 0.5 C rate charging.
I hope I don't have to explain the difference between charging voltage and voltage being charged.
After disconnect, voltage will drop quickly, in a few days down to 3.45v.
Yes, under the 3.65, still 100% charged.
Why does everyone advise to stop at 3.65?
If you ever witnessed the rapid increase in voltage after the reached 3.5v you know why.
Up to 3.5v takes hours, beyond minutes to reach 3.65 and over.
Will you damage your cell by charging above 3.65?
No. Not directly. You can stretch up to 4.2v before damage occurs.
Yet, charging to 100% is already destructive for the cell.
Best to stay around 90%
Bottom Balance
Most BMS stop at 2.5v.
Like they stop at 3.65v
Doesn't mean it's damaging to go little under or over!!
For LiFePO4 it's 2.0 as bottom, not 2.5v
Again, if you ever have witnessed how fast the voltage drops under 2.8v (or even 3v) ..
There is "no" additional charge beyond 3.65, and "no" additional discharge beyond 2.5v
"No" is not nothing.
Perhaps 0.5Ah if you stretch/squeeze it.
Having your LiFePO4 cells at 2.0v is just as damaging as having then at 2.5v.
LiFePO4 doesn't like fully charge or discharge.
There is no additional damage at 2.0 or 2.5v
For the people who aren't watching like a hawk their cells when doing initial Balance, the first balancing action to get your new, or already used cells in line to start building your pack..
If you are active member of the forum long enough you know how many users damaged their cells (bloating) during the top Balance...
Most users don't have special lithium charger capable of 3.65v.
Or BMS that handled 1 cell.
Yet, to balance the initial pack, it's going to be one long row in parallel.
Like one massive "3.2v" (nominal voltage) cell.
With this, one is "asking for trouble" and often getting it!
Alternative of top Balance is bottom Balance.
Discharge. Resistor, lightbulb, you name it what is available for you to use.
Funny fact, going below 2.8 goes slower then charging above 3.51.
With the same charge or discharge you have more hours time to stop after that "elbow"
Most people have work or sleep at night, they don't have time to look every few minutes.
That means that the cells will be unattended for hours and hours.
And that is where the trouble start.
For the initial balance, bottom balancing is a lot safer then top balancing.
To many users already have the scars to proof this.
For normal usage, yes I stay between 10 and 90%.
And I don't even need to top/bottom balance at all!
With my active balancer it's always being corrected without much loss.
Moving energy always cost.
Few watts a day. Still.. cost
Any BMS will cost also, most probably more.
For me, that is the best way to go.
After the initial balance to get the cells in the same line.
And that initial balance best can be bottom balance, what is a lot safer for your cells then top balancing.
Unless you spend $$$ for special charger to use 1 time and special BMS to use 1 time.
Most people aren't building may battery array's
