Not now, not ever. BTW, the same problems show up frequently for the Kindle Fire. I've taken (i.e. plagiarized) FoxKat's procedures for re-syncing the battery charge and monitor and posted them on several Kindle Fire forum websites, including the Amazon Kindle Forum. A number of reports indicate that the procedures help tremendously and have resulted in some very happy KF users.
Very nice! I am not surprised that the cure is transportable to either other models of phones, or even to other devices like the KF. This method of care will apply to most devices that operate on LI or LIPO batteries, and it only makes sense since it's the battery's unique charging and discharging profiles that actually CAUSE the divergence between the actual capacity levels and what the meter believes and represents them to be at any point in the charge/discharge range.
This issue will be far less pronounced in devices which use relatively high current in bursts and then resting periods in between such as power tools. Since the power tools will only run when high current is available and they are less sensitive to voltage per se', and far more sensitive to current (higher voltage causes higher RPM, but current carries the resistive load - such as while drilling or sawing). By having periods of time in between bursts of use to allow the battery to "recover", the battery is better prepared to dump all available current at maximum load quickly.
Once the battery is depleted to a point where the current is insufficient to run the tool (turn the motor) with any respective load, the voltages begin to drop dramatically at the first sign of any load and the tool slows down and eventually stops. Also, there is no "meter" to display charge level in most of these devices, and instead the obvious indication it is discharged is when it no longer performs its duty. There IS metering and health detection circuitry in the charging stand that these batteries slide into and it's there, again unimpeded by any load from the device, that the charger is able to accurately determine the health and charge capacity of these batteries.
In devices where the draw is relatively small but the voltage is more important - such as these computer devices, these batteries will first show a high voltage (4.2 - 4.3 volts) at the onset of the first 20% of the top of the charge but roll off rather quickly from 100% to 80%, then tend to provide a relatively stable voltage of over a wide range of the charge capacity between 80% and 20%, and then will begin to roll off again as it approaches about 20%. This is why draining to 15% is sufficient for the circuitry to recognize the battery is nearing its last remaining capacity and so it's able to set the discharge flag at that level, but ONLY after a full charge to 100%, so the circuitry "sees" the full range of capacity.
In the case of the OP, his meter was so far out of calibration that it still had far more than that available hence being able to listen to music for 7 hours while the meter incorrectly displayed only 5% The only way to resolve that issue is to shut off (as he did), then charge to 100% with power off (to enable the charging and metering to see ONLY the battery draw), and then discharge to 15% and repeat. This allows the meter to get a true representation of what the battery profile looks like at a full charge, where the initial 20% roll off occurs (from 100% to 80%), gauge the period between 80% and 20%, and then finally see the final roll off at 20% heading toward 15%.
