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Re: battery life

> > Yep, that's what I noticed as well (in MacOS, not Linux). What's the
> > voltage calibration? My battery starts at a reading of 11911 ...
> I suppose, at least for my TiBook, that it's simply mV. That would match
> the fully-charged/end-of-discharge voltages I see for my battery pack (4
> graphite Li-ion cells in series) on the TiBook.
> Are you sure you have the same battery technology? Your end-of-discharge

Nope, just that I have the same battery type as the Pismo machines.

> of just above 10V suggest that you may have Li-ion cells with coke
> cathodes (older technology). On those, however, you should also reach
> 4.2V per cell when fully-charged, vs. 4.1V per cell on graphite.

I rather guess 10000 equals 12 V. I'd like to find a way to test these
batteries outside the computer (as in, hook up a dummy load and so on).
There seems to be more to it than just connecting the two outermost leads,
though (no current drawn).

> > I gave in and ordered a replacement battery from a third party
> > distributor. They must have bumped battery capacity in the Pismo
> > models, max charge of the new one is 5400, that lasts about 3.5 hours.
> It could be more recent battery technology. Did you know there's a
> standard for smart batteries? There's a whole site about that:
> 	http://www.sbs-forum.org/

Gives the same 'full' voltage readings, at least. When full and on AC, it
shows 12315 (no load drawn so voltage should be higher).

I'll check that site for more details. Maybe they have a battery pinout or
test circuit diagrams...

> AFAIU, these batteries _always_ include the microprocessor controlling
> the charging, and giving the capacity readings, inside the battery. That
> makes sense... And it means PMU reset probably has no influence on
> battery capacity.

Well, deep (down to cutoff) discharge bumped max charge from 1745 to 1861
:-) No PMU reset, just draining it with root remounted ro.

> > Weird things happen with both batteries installed: with AC connected,
> > at least the big one is continously discharging a bit then recharging.
> I wouldn't know for sure, but depending how both batteries are connected
> together, weird things could happen... although I imagine Apple's
> engineers be smart enough to couple both batteries via protection diodes
> preventing the lower-voltage battery discharging the higher-voltage one
> :-)

That's for sure. The PMU seems to get confused there.

> > The old one starts at 11900, ends around 10530.
> Hmmm, fully charged at 12V? That doesn't sound like Li-ion cells... That
> could be 10 NiMH cells in series. But I may be wrong...

It says Li-Ion on the battery, though.


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