Re: Adjust speed of fan

On Mon, 5 May 2008 18:38:31 -0400, "BillW50" <BillW50@xxxxxxx> wrote:

In news:cvvu14l2a0t4dfdjkhbquir8m14cpdbo2i@xxxxxxx,
RnR typed on Mon, 05 May 2008 16:56:30 -0500:
On Mon, 5 May 2008 17:36:48 -0400, "BillW50" <BillW50@xxxxxxx> wrote:

In
news:12da2359-c4db-44a3-aab5-c4f904accc98@xxxxxxxxxxxxxxxxxxxxxxxxxxxx,
dontdont@xxxxxxxxx typed on Mon, 5 May 2008 11:04:29 -0700 (PDT):
On May 4, 2:11 pm, "BillW50" wrote:
...
Just look at laptop designs. I personally feel that charging
Li-Ionbatteries up to 4.2V per cellis a *huge* mistake! But all
major laptops are designed to do so. I feel charging them only to
4.1V per cell and they will last almost twice or longer.

Is there a dependable way for a user to limit charging and extend
life on laptops that do not provide an option to control this?

Removing the battery while on AC power seems to be the most and
easiest method. If you use your laptop on battery a lot, well it
gets more difficult.

Is there a document out there somewhere that graphs maximum
charging voltage versus battery life and versus use time per charge?

Yes, I believe I have seen such graphs somewhere. Here are some tests
that might help you a bit.

http://www.rcgroups.com/forums/attachment.php?attachmentid=406687
http://www.rcgroups.com/forums/attachment.php?attachmentid=406910

See also section 4 of this PDF as well.

http://www.schulze-elektronik-gmbh.de/guide/glipob-e.pdf

Thank you for your expertise and information

You are welcome.

Bill, maybe this is an easy question or not but I know it's come up
before and I ask ("respectfully") only for information purposes not to
start any argument or flames from me or others...

Sure no problem. :-)

Using a laptop, for the sake of battery longevity, do you think it is
better to keep it installed or uninstalled when using electricity to
run it. I'm aware that the battery is a sorta ups in certain
instances but I'm only interested in regard to longevity for this
post.

Oh removing the battery for sure. There are many reasons why this is a
great idea. One is the heat slowly kills them for one. Secondly they all
being recharged a lot which also reduces their life. And keeping it
charged at 4.2v per cell or even 4.1v per cell isn't that good for them
for the longterm.

Many experts say storing them at 40% charge is ideal. Although sitting
on the shelf they will slowly discharge anyway. And I have found
charging them up to even 100% and letting them sit doesn't harm them if
you rarely use them anyway. As that gives you at least a year before you
should recharge a sitting Li-Ion battery. Many have stated that you can
make them last 10 or more years under these conditions, including
myself.

The only thing to worry about is recharging them after they self
discharge. As Li-Ion chargers have many protections build in usually
(including laptops) so to prevent explosions and fire. And one of the
protections is to disallow charging if the battery voltage drops too
low. Sometimes the circuit is in the battery or the laptop itself. So
you should be careful to not let the capacity to drop too low. Otherwise
the battery becomes pretty worthless.

Just to add to this, I recall reading (I think on Dell's web site)
that the batteries were rated for about 800 to 1000 recharges (I
forgot exact number right now) which might be of some help to others.
I wish I kept that link but perhaps I can find it again or someone
else can.

Well full recharges is said to be 500 times maximum. You could get 800
to 1000 half recharges out of them. But these numbers is under perfect
conditions. Realistically you should get half or a bit better recharges
with some care.

Remember if you are using battery power all of the time, these are the
numbers you are hoping for. And the number of recharges is what is going
to kill the battery. Although if you rarely use battery power, you will
never get hundreds of recharges. As leaving it in the laptop all of the
time and on AC will buy you about 18 to 24 months worth and then the
battery will be worthless without even using it once on battery power.

Some argues that without the battery in the laptop on AC, if the AC
fails the laptop turns off. This is true. But in this case, buying an
UPS (Uninterruptible Power Supply) is cheaper than Li-Ion batteries and
you can plug in other AC things like lamp, cordless phone, etc. Those
that can run a laptop can be had for about $30 or less if you shop
enough for the deals.


Bill, thank you very much for a well informative post.
Truly appreciate your effort to take the time to explain it in detail.
:-)

-RnR-

ps--- I want to apologize in advance to you because now everyone will
know you are the electronic genius that you are and will expect you
know it all :( . Sorry I didn't think about this before my earlier
post.
.

Relevant Pages

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