[geeks] anyone know Vaios?

[Mouse]

>> According to envstat -r, the battery is at 100% charge, but its
>> voltage is only some 3.9V, vs a design voltage of 11.1V.

[jkunz]
> There is somthing fishy.  11.1 V / 3 = 3.7 V and this is the nominal
> / average voltage of a LiIon cell.  Minimal discharge voltage is,
> depending on cell type, around 3 V. So you should have at least
> around 9 V when the pack is fully discharged.  [...]

> The cells in that pack are dead.  The BMS detects this due to the
> undervoltage.

[alaric]
> My assumption would be that the controller has allowed cells to drift
> outside of the very narrow charge range allowed for a lithium-ion
> cell, and you now have only one working cell bank in the battery.
> IT's reporting fully charged, but that doesn't help you.  If it's
> reporting the battery pack fully charged at 3.9V, the pack's toast.

Best-functioning dead battery I've ever seen.

I left the machine to run itself out of battery, saving a timestamp and
envstat -r output every minute.  (It was of course on AC power, with
the battery reporting full.  So I set up the self-monitoring, shut off
AC, and left it until it ran out.)

It lasted approximately an hour and three-quarters, which is about what
its battery life has been for the last year or so.  And now, with AC
power back, the lights are showing its normal charging blink pattern
and envstat -r says its charge rate is 14.64 W, which also is about
what the last year or so of experience with that machine and battery
pack has led me to think of as normal.

So now I'm wondering if maybe there's always been only one working cell
for the whole time I've had it.  If the discharge rate reported during
my discharge run is accurate, the pack holds between 26 and 27
watt-hours.  It's marked as 11.1V 4800mAh, which is 53.28 Wh.  That's
about twice the above figure, not three times, leading me to be
thoroughly puzzled by this whole mess and wondering if perhaps there's
something broken in the self-monitoring such that at least one of the
figures reported is bogus.

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