[TriLUG] Thinkpad Battery Charging Thresholds

[Robert Dale]

I guess I have a different interpretation.

Going by the chart - throwing-out 40C and 60C since I don't work in
the desert for prolonged periods of time; I typically work in balmy
indoor 25C weather - I can still run my laptop twice as long on 80%
batteries over 40% of 96% capacity which is 38.4%. Even if you charge
up to 80%, you still only have 76.8% available. And if you stop
working at 30% then you can still only get 46.8% usable battery. Which
may be very well and good if you're using your laptop battery as a UPS
instead of a means to be mobile.

I don't see in the article where it mentions a specific range of 30%-
80%.  The articles does stress that temperature and charge _rates_ are
more of a factor than charge cycles and levels.

I'm slightly confused by the mention to not freeze your battery when
the lab results were best at 0C.

I don't know theirs or your particular battery/laptop setup, but the
laptops that I've had in the past year or two don't keep the battery
temperature elevated when not actually charging the battery.  The
power supply or something seems to be smart enough to stop charging at
a certain point.

Everyone's situation is different,  but in my real life experience,
battery lifetime appears to be long enough that the effort required to
baby-sit the battery isn't worth it. Even if you took 2 minutes every
work day, that's 8 hours of baby sitting time.  A baby-sitter
typically makes $12/hr.  So, at the end of the day, I've done no extra
work, wasted no time and get 80% of my battery, while you've wasted
$96 on baby-sitting and realized only 47% of your battery's potential.

:-)

On Tue, Feb 15, 2011 at 7:37 PM, Joseph Mack NA3T <jmack at wm7d.net> wrote:
> On Tue, 15 Feb 2011, John Brier wrote:
>
>>> I know that optimally the battery
>>> should be between 30 % and 80 % of full charge
>>
>> Where did you hear this?
>
> how about google
>
> http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
>
> o keep batteries cool (pull them out when the laptop is plugged into the
> mains)
>
> o don't full charge
>
> o charge slowly
>
> Prius batteries are normally charged to about half full.
>
> Satellite batteries are nursed carefully. They aren't allowed to be fully
> charged.
>
> Joe
>
> --
> Joseph Mack NA3T EME(B,D), FM05lw North Carolina
> jmack (at) wm7d (dot) net - azimuthal equidistant map
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-- 
Robert Dale