Quote:
Originally Posted by TBennettcc
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So far as I understand, my friend tried to turn on the device, and it showed the "empty battery-plug me in-recharge me" screen. Someone told him this meant he needed a new battery, so he bought one and put the new battery in.
As far as how it got to that point, I'm not sure. I don't know which screens, if any, he saw before the "plug-in-to-charge" screen. I don't know if it tried to do an update first, and failed, and showed the "failed update" screen before it showed the "plug-in-to-charge" screen.
Is it possible it was trying to do an update, and the battery died in the middle of the update?
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The unfortunate answer is:
**YES**
The design of the firmware protects the system from attempting an update in the case of a **SINGLE POINT** failure - -
Specifically, a low terminal voltage on the battery.
(Same measurement triggers the "need more juice" panel.)
The (faulty) assumption in the design is that the terminal voltage is an indication of the storage capacity (available).
Ah, but LiIon batteries do not age in that manner.
Terminal voltage measurement only indicates if the battery is **FULLY Charged** to its **current** capacity.
But what is
FULL ?
In the case of a relatively new battery, about 1.5 amp/hours.
In the case of an old (and/or heavy used/cycled) battery, maybe less than that of a small hearing aid battery.
When **FULLY Charged** both case will show a *normal* full-charge terminal voltage.
But the stored energy will not be the same, in one case (new) it will be a lot, in the other case it will be not even worth mentioning.
Duh.
A **TWO POINT** failure -
1) Insufficient storage capacity to complete the high power consumption erase/re-program cycles needed to re-write the flash.
2) Only testing the terminal voltage, not testing the capacity.
Translation:
Its toast.
(or spare parts - except for the flash chip - that thing is destroyed)
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The only good news is:
Neither you nor your friend had anything to do with this failure.
And it probably happened **before** the battery was changed.
The conditions back then:
1) A battery with little storage capacity (due to use/age);
2) The presence of an update file.
The system tried to run an "auto install update" and ran out of power while the flash chip was getting one of its erase/re-program cycles organized (the battery has a tiny micro-computer in it).
Result: It self-destructed.