[ltp] Laptop battery storage

[Torsten Wagner]

Hi,

as far as I know the problem with LiON battery is quite unknown for 
selling reasons. However, Li is a very instable material. Not in terms 
of radioactive :), but it likes to combine with a lot of different other 
materials.
The big secret is, that this happens independent whether you use the 
batteries or not.
Hence, to store a brand new LiOn battery for longer then 2 years is also 
stupid.

If you buy a good brand which includes branded cells, they will be well 
sealed and protected. Worse brands, which you might have to expect in 
cheap laptops, have a much higher natural aging.

The aging will for sure increase by lots of charging and discharching 
cycles. However, I do not think about that the battery stuff is a real 
problem. I don't want to save half a year battery life with the trouble 
I may get by using my laptop without battery (missing the natural 
UPS-function of a notebook).

More critical is there more and more increasing power consumptions, 
which might not be longer provided by standard battery packages. AFAIK, 
LiON batteries are not high-current capable. That's the reason why they 
are not used for RC-Cars etc. It seems we might reach this limit 
already. I noticed a definitive decrease of battery performance on new 
laptops. If you use LiON batteries with high currents, the aging is 
amazing fast (as well as the self-heating effect).

Lets wait for the first Thinkpad with fuell cell.


Just my two cents.

Torsten



Mendel Cooper wrote:
> Again, possibly discussed before.
>
>
> If you're not running your laptop on battery power, it's a good idea to
> remove the battery and store it. That prolongs its life. It's recommende
> that they be stored at about 50% charge (Why? I don't know.)>
>
> Why? Because those wonderful "smart" LiON batteries only have a limited
> number of charge cycles, something in the range of 200 - 300 or so. And,
> there's an electronic counter inside the battery that keeps count and
> irrevocably turns off the battery when the count is full up. Very clever.
>
> Now, when you keep the battery inside the laptop, even running on AC all
> the time, the battery charge trickles down a percent or two a week. And,
> when the charge drops to 95% *, the BIOS senses this and recharges it
> back to 100%. And, guess, what? That counts as one charge cycle. So,
> in about a year and a half you can use up a brand spanking new battery
> without ever actually using it. Very clever indeed.
>
>    * In some older laptops, the recharging would start at 98%.
>
> Sometimes, those "smart" gadgets are too damn smart for their own good.
>   

-- 
----------------------------------------------------
Dipl.-Ing. Torsten Wagner, MSc 
University of Applied Sciences Aachen Campus Juelich
Laboratory for Chemo- and Biosensors
Ginsterweg 1, D-52428 Juelich, Germany
Tel.: +49 2461 993215 or 612466
Fax: +49 2461 993235
Email: torsten.wagner@fh-aachen.de
and
Research Centre Juelich GmbH
Institute of Thin Films and Interfaces (ISG-2)
D-52425 Juelich
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