I guess most of the flows in the library are not tested on every single android device. I would therefore (maybe it is declared in a form of EULA, warranty regulations etc.) expect using any of them is anyones own risk.
But as a startpoint for other FP2 users it would be valuable.
I would also agree to what @Javi_VM has written. As some kind of charging routine kicks in as soon as there´s some kind of power source connected without the OS even being booted. I guess it´s directly implemented in the SoC
where you only can get after boot time by modifying a kernel module.
I believe root access won´t get you much further here.
Interesting flow, btw. Makes me remind a form of Siemens S7 function diagram.
Do you remember how long it took for you to have it working to your needs?
In one way you are right, I think I can follow your thought. But this is also somehow contradicting. Yes, you want to reduce heat development while charging - But the phone is in use meanwhile.
Imagine you are doing cpu/gpu intense actions like playing back/streaming HD video (playing Pokemon Go…). Now there is a high power demand already. To push more energy into the battery instead of having it discharged while being plugged you will have to overcome the boundary. This leaves you again with a high charging current alongside with the use. I am afraid it would not work this way.
I don´t want to question your competence in this field.
Of course this would limit the current and cause less heat development. After all it then depends on what you are doing with the phone. Watching images ok, but other actions…??
Several users already had reported about having troubles with a battery discharging even more whilst being plugged. It is not yet commonly known (since being a technical subject) how this charging mechanism works. Nevertheless this problem occurs also due to the fact that there is no original FP charger provided with the phone. Therefore users take what they have at hand. Sometimes they are lucky and all matches well, in some cases tough it does not.
Again I agree here.
This is a very interesting point you are mentioning. Many users commonly believe doing so should help when having troubles with other (AC) chargers.
From the batteryguide
I don´t want to question anyones competence in this field. Often there is personal experience covering such statements.
I have built a few usb cables in the past for my personal need.
For USB 2.0 data lines does not transmit power (different with USB3.0). So it does not matter if using a cable with 2 or 4 wires. But the used wire gauge of the wires does matter a lot here. Actually that´s the limit for the current (wire gauge and specific wire resistance/conductance). Someone may have a strong all purpose USB charger providing 3 Amps (no fixed cable, but with usb socket). Connecting a cable with too thin cable diameter won´t get them far. Most, not all ac chargers don´t know what they are dealing with anyway. So it won´t make a difference if there are 2 or 4 wires. (power output is only on USB pin 1+4). A µUSB connector has 5 pins but cannot make more use of it unless it´s a OTG adaptor.
Any cable 2/4 wires (all with proper wire gauge of course) may deliver more current for faster charging (FP2 actually has no quick charge feature enabled). The highest I could measure was about 1,4Amps.
Depending on if available and how the data lines are connected to the “power source” - may it be a computer usb output, the data mode may be enabled, limiting the current or no data mode is enabled hence proving all the current the usb port can deliver (relying to official USB specifications).
There is only little help when plugging an usb 2.0 plug into a 3.0 socket. It could deliver slightly more current, but far from what usb 3.0 could do with a compatible 3.0 device (needing at least a corresponding usb-c connector and proper cable with even more wires of course). Current/wire gauge isn´t the limit here as it can also work with different voltages but 5V dc.