New Droid RAZR Maxx!

[Ghostwheel]

Really interesting stuff, thanks for putting it all together - I'm an engineer with a physics background, so I comprehend the technobabble.

In regard to the "bump charging" part, I thought that there were internal mechanisms (hardware or software) in place in Droids that kept them from attempting to overcharge once 100% capacity was reached. Not knowing the actual system schematics, I could be wrong, but I swear I remember reading something to that effect when I first got my D1.

Either way, I think the chart showing percent discharge and number of cycles will help me refine my charging habits. With an anticipated phone life of 2.5 years, I don't want to start encountering significant low battery life issues before then.

 

[FoxKat]

Really interesting stuff, thanks for putting it all together - I'm an engineer with a physics background, so I comprehend the technobabble.

In regard to the "bump charging" part, I thought that there were internal mechanisms (hardware or software) in place in Droids that kept them from attempting to overcharge once 100% capacity was reached. Not knowing the actual system schematics, I could be wrong, but I swear I remember reading something to that effect when I first got my D1.

Either way, I think the chart showing percent discharge and number of cycles will help me refine my charging habits. With an anticipated phone life of 2.5 years, I don't want to start encountering significant low battery life issues before then.

No, you are 100% correct. The problem is these circuits can be "fooled" into believing the actual "resting" voltages of the battery are low - low enough that the charging circuitry believes the battery isn't yet at its fully charged state due to the phenomenon known as s parasitic load ("A parasitic distorts voltage-based SoC readings.") This ends up in the charging circuit allowing either additional "topping off" current (which is considerably reduced from the full charging rate, i.e. .5C versus 1C), or can even believe it has not yet reached the signature current drop and voltage peak to indicate it has reached or exceeded that point and result in full charging current for a period of time (i.e. 1C).

These two situations although markedly different in risk are both risky and both result in at the very least additional stressing of the battery due to over-voltage. In the worst case scenario it can cause a "thermal runaway" that can end in catastrophic failure. This is why it is inherently safer to charge with the power off, so the current and voltage draws of the phone don't artificially depress those values and cause the situations above or allow "bump charging".