On Mar 17, 12:22 pm, Olaf Kaluza wrote:
> p.s: Of course you need a selfmade lithium battery charger, but that
> is to complicate for this newsgroup. .-)

If you use the MAX 1555, like I did in my lithium powered 49g+
http://jeisch.googlepages.com/hp-49gplus the charger is pretty
simple. I used the usb input, but it can also take any DC source
between 3.7 and 7 volts.

I like that you fit the whole thing in the battery compartment. Good
job.

-Jonathan

bokubob wrote:


>If you use the MAX 1555, like I did in my lithium powered 49g+
>http://jeisch.googlepages.com/hp-49gplus the charger is pretty
>simple. I used the usb input, but it can also take any DC source
>between 3.7 and 7 volts.

I charge my battery with a selfmade charger I build with a
microcontroller that can charge/discharge, measure Ri, Capacity and so
on.

If I like to build something inside of calculator I can recomend BQ24108
from Texas. It did not waste so much space and you can use 6-16V. That
is good for charging in cars.

I used it for my PDA powersupply:

http://www.criseis.ruhr.de/powerbox/powerbox.html

Perhaps you can steal the idea or a part of the layout, because it is
complicate.

Olaf

Olaf Kaluza wrote:

> Fit very well and in 1-2 years I can say how long I can use between
> charging.

Why use rechargeable lithium-batteries?

When the alkalines, i have actually in my 49g+ are empty, i will replace
them by non-rechargeable lithium batteries.

I think that should be enough energy for the next 3 - 4 years

The problem of lithium-accumulators is, that they have a very short
lifetime. Only 3 years, sometimes a bit longer but with a significant loss
of capacity.

Volker
--
Im übrigen bin ich der meinung, dass TCPA/TCG verhindert werden muss

Volker Neurath wrote:


>Why use rechargeable lithium-batteries?

Because battery become empty only at weekend!

>The problem of lithium-accumulators is, that they have a very short
>lifetime. Only 3 years, sometimes a bit longer but with a significant loss
>of capacity.

No, thats wrong. For example the battery of my Zaurus SL-C750 is now
5-6years old and I can use it for 5-6h without any problem. (2h with
WLAN on)
And I have many (5-6) torches with lithium battery. I made them myself
with old battery from laptop and they are working very well.

Oh..and I bought 20 of lithiumbattery that I used for my 48SX at ebay
for only 11.50Euro...

Olaf

On Mar 20, 12:20 pm, Volker Neurath wrote:
> Why use rechargeable lithium-batteries?
>
> When the alkalines, i have actually in my 49g+ are empty, i will replace
> them by non-rechargeable lithium batteries.
>
> I think that should be enough energy for the next 3 - 4 years

You mean like Energizer 1.5V lithium AAAs? Like these:
http://data.energizer.com/PDFs/l92.pdf

As you can see, the capacity of lithium batteries at low power draw is
the same as alkaline. Only at high discharge rates (>200mA) does the
internal resistance matter enough to reduce the effective capacity.

If you go back to Eric's thread on current draw for the hp 50g:
http://groups.google.com/group/comp....r+consumption#
you'll see that the maximum draw in a 50g is 92.0mA.

So, if you look at the capacity at 100mA on the energizer spec sheet,
you'll see that your lithium would have an effective capacity of
1200mAh, where an alkaline has a little over 900mAh.

So, you might be getting something "better" than the energizers, but
since lithium and alkalines are basically identical at low current, I
don't see where your excitement comes from.

You'll spend about the same amount on your non-rechargeable as I paid
for mine, but mine is... you know, rechargeable.

-Jonathan

> The problem of lithium-accumulators is, that they have a very short
> lifetime. Only 3 years, sometimes a bit longer but with a significant loss
> of capacity.

It's not a time issue, is a charge, recharge issue. Probably figure
at least 100 recharge cycles before the capacity drops noticably. I
dare say, in a calculator, that will be a bit more than 3 years.

Please feel free to inform me of facts that I'm not aware of.

Cheers,
-Jonathan

bokubob wrote:


>Please feel free to inform me of facts that I'm not aware of.

When a lithium-battery becomes old you will find at first that the
inner resistance goes up. This is a big problem for high power devices
like a laptop. But if your device needs very low power than you can
use the battery very long.

For example, I wrote I build some torches myself. One of them I made
7-8 years ago. I used two 18650cells from a _bad_ old laptop battery at
this time. Four years ago I used this torch in my garage for
repairing my car. After that I forgot the torch there and found it one
year ago. So it stays there three hot summer and three cold winter.
I switched it on and it worked without a problem, it was even well
charged. I tested it because I was interested about it.

For this reason I expect a very long live of lithium battery inside my
HP48SX.

Olaf

bokubob wrote:

>> I think that should be enough energy for the next 3 - 4 years
>
> You mean like Energizer 1.5V lithium AAAs? Like these:
> http://data.energizer.com/PDFs/l92.pdf

Indeed.

> As you can see, the capacity of lithium batteries at low power draw is
> the same as alkaline. Only at high discharge rates (>200mA) does the
> internal resistance matter enough to reduce the effective capacity.
>
> If you go back to Eric's thread on current draw for the hp 50g:
>
http://groups.google.com/group/comp....r+consumption#
> you'll see that the maximum draw in a 50g is 92.0mA.
>
> So, if you look at the capacity at 100mA on the energizer spec sheet,
> you'll see that your lithium would have an effective capacity of
> 1200mAh, where an alkaline has a little over 900mAh.
>
> So, you might be getting something "better" than the energizers, but
> since lithium and alkalines are basically identical at low current,

Ok, that ist the reason why i felt that in the lithiums in my tv's remote
control didn't do much longer than the alkalines.

> I don't see where your excitement comes from.

Besides the 49g+ i call an HP IR printer my own. And in the printer, the
lithiums outclass the alkalines - i testet that several times.

>> The problem of lithium-accumulators is, that they have a very short
>> lifetime. Only 3 years, sometimes a bit longer but with a significant
>> loss of capacity.
>
> It's not a time issue, is a charge, recharge issue.

This is true for non-lithium accumulators but not for lithiums.

Lithium accumulators suffer from a significiant loss of capacity after about
three to five years, regardles wether used or not and regardles if stored
fully recharged, partly recharged or empty.
--
Im übrigen bin ich der meinung, dass TCPA/TCG verhindert werden muss

On Mar 21, 11:58 am, Olaf Kaluza wrote:
> For example, I wrote I build some torches myself. One of them I made
> 7-8 years ago. I used two 18650cells from a _bad_ old laptop battery at
> this time. Four years ago I used this torch in my garage for
> repairing my car.

Every once in a while, the differences in meanings between American
English and British English can be somewhat humorous (er, uh,
humourous). In light of regular reports of the behavior (behaviour)
of laptop batteries, I found this to be such a case.

"Sony Laptop Battery Torches Desk"
http://blog.wired.com/gadgets/2007/0...aptop_bat.html

Let's hope your garage and car faired better with your "torch" than
the desk did.

-wes

In article
<2cc21152-aabc-40ef-9de3-96cdb5b39e0e@c65g2000hsa.googlegroups.com>,
Wes wrote:

> On Mar 21, 11:58 am, Olaf Kaluza wrote:
> > For example, I wrote I build some torches myself. One of them I made
> > 7-8 years ago. I used two 18650cells from a _bad_ old laptop battery at
> > this time. Four years ago I used this torch in my garage for
> > repairing my car.
>
> Every once in a while, the differences in meanings between American
> English and British English can be somewhat humorous (er, uh,
> humourous). In light of regular reports of the behavior (behaviour)
> of laptop batteries, I found this to be such a case.
>
> "Sony Laptop Battery Torches Desk"
> http://blog.wired.com/gadgets/2007/0...aptop_bat.html
>
> Let's hope your garage and car faired better with your "torch" than
> the desk did.
>
> -wes

Was it G.B.Shaw who remarked that Great Britain and the United States
were two countries separated by a common language?

Wes wrote:

> Every once in a while, the differences in meanings between American
> English and British English can be somewhat humorous (er, uh,
> humourous).

I fear the humour is not so easy to see if your mother language
is German. .-)


> "Sony Laptop Battery Torches Desk"
> http://blog.wired.com/gadgets/2007/0...aptop_bat.html

> Let's hope your garage and car faired better with your "torch" than
> the desk did.

Hhm I will read your link later, because this email is writen in my
garage with my beautiful Zaurus and his nice LCD that needs no torch.
:-D


Olaf

olaf@criseis.ruhr.de wrote:

> Wes wrote:
>
>> Every once in a while, the differences in meanings between American
>> English and British English can be somewhat humorous (er, uh,
>> humourous).
>
> I fear the humour is not so easy to see if your mother language
> is German. .-)

Huh? that't easy, try www.leo.org

But i'll try to explane it:

"torch" is one word for the german "Taschenlampe" - but only in british
english.
In american english "torch" ist a person who lights something in order to
destroy it, and "to torch" means just that: to light s.th. to destroy.

Teh correct word fpr "Taschenlampe" in american english is "flashlight"

Volker
who is, like you, NOT an english person
--
Im übrigen bin ich der meinung, dass TCPA/TCG verhindert werden muss

> > I fear the humour is not so easy to see if your mother language
> > is German. .-)

Sorry, I should have explained.

> But i'll try to explane it:
>
> "torch" is one word for the german "Taschenlampe" - but only in british
> english.
> In american english "torch" ist a person who lights something in order to
> destroy it, and "to torch" means just that: to light s.th. to destroy.
>
> Teh correct word fpr "Taschenlampe" in american english is "flashlight"
>
> Volker
> who is, like you, NOT an english person

This is correct, but for americans, the most common use of "torch" as
a noun always refers to something that has an open flame, such as the
Olympic Torch, or what you would see being carried through the jungle,
or a gas torch used in welding.

Your usage was perfectly correct, it's just that with all the news
reports, the thought of _trying_ to create a flaming torch from your
laptop battery struck me as being funny.

-Wes Loewer (or Löwer as my Großpapa spelled it, uh, spelt it)

Wes wrote:

> This is correct, but for americans, the most common use of "torch" as
> a noun always refers to something that has an open flame, such as the
> Olympic Torch, or what you would see being carried through the jungle,
> or a gas torch used in welding.

I know, but i just forgot to mention this.

> Your usage was perfectly correct, it's just that with all the news
> reports, the thought of _trying_ to create a flaming torch from your
> laptop battery struck me as being funny.



That's why i referred to "flashlight" instead of "torch".

>Wes Loewer (or Löwer as my Großpapa spelled it, uh, spelt it)

German too?

Volker
--
Stop TCPA/TCG now!

On Mar 23, 1:49 pm, Volker Neurath wrote:

> >Wes Loewer (or Löwer as my Großpapa spelled it, uh, spelt it)
>
> German too?

In heritage, yes, but the only German I heard growing up was when my
parents used it as the "secret parent language."

-wes