On 15 Jan 2007 17:51:06 -0800, "lsmartino"
wrote:


Rod Speed ha escrito:

Not necessarily. They can move the charging circuit to the cell in itself.

Not practical with AA and AAA batterys being discussed.

In spades with an ipod battery.


Why? Because you say it? Oh please...


Of course that will steal space from the chemical part of
the cell with the resultant capacity loss, but it can be done.

But isnt practical and it cant be done with an ipod battery anyway.

Thus the charger used to recharge the battery becames
inmaterial because any proper voltage source will suffice.

The problem aint the voltage source.

You say that because probably you don´t have a clue about how a
battery charger works.


In fact, since lithium cells produce 3V, and a AA battery
shouldn´t produce more than 1.5V, I suspect that these
lithium cells have some form of voltage regulating circuit inside.

No, there are different "lithium" chemistries, and the Energizer E2
Lithium is a native 1.7 or 1.8 volt cell. AA cells are roughly 3 ah
each, and loose less than 1% per year to self discharge.

Here's a bit of info on 1.5 volt nominal lithium chemistry. From
http://en.wikipedia.org/wiki/Lithium_battery

Li-CuO Copper oxide 1.5 V 2.4 V
Can operate up to 150 °C. Developed as a replacement of zinc-carbon
and alkaline batteries. "Voltage up" problem, high difference between
open-circuit and nominal voltage. Produced until mid-1990s, replaced
by lithium-iron sulfide. Current use limited.
Li-Cu4O(PO4)2 Copper oxyphosphate
See Li-CuO
Li-CuS Copper sulfide 1.5 V
Li-PbCuS Lead sulfide and copper sulfide 1.5 V 2.2 V
Li-FeS Iron sulfide Propylene carbonate, dioxolane, dimethoxyethane
1.5-1.2 V
"Lithium-iron", "Li/Fe". used as a replacement for alkaline batteries.
See lithium - iron disulfide.
Li-FeS2 Iron disulfide Propylene carbonate, dioxolane, dimethoxyethane
1.6-1.4 V 1.8 V
"Lithium-iron", "Li/Fe". Used in eg. Energizer lithium cells as a
replacement for alkaline zinc-manganese chemistry. Called
"voltage-compatible" lithiums. 2.5 times higher lifetime for high
current discharge regime than alkaline batteries, no advantage for
low-current applications. Low self-discharge, 10 years storage time.
FeS2 is cheap. Some types rechargeable. Cathode often designed as a
paste of iron sulfide powder mixed with powdered graphite. Variant is
Li-CuFeS2.
Li-Bi2Pb2O5 Lead bismuthate 1.5 V 1.8 V
Replacement of silver-oxide batteries, with higher energy density,
lower tendency to leak, and better performance at higher temperatures.
Li-Bi2O3 Bismuth trioxide 1.5 V 2.04 V

The E2 is Lithium Iron DiSulphide.

They have a self protection circuit built in - a self resetting
poly-fuse type apparatus callet a PTC (Positive Temperature
Co-efficient) This also makes it almost impossible to detonate the
battery by attempting to recharge it. The battery is limitted to 2
amps continuous, but can handle short duration higher peaks
significantly higher.
They CAN BE SHIPPED BY NORMAL METHODS INCLUDING MAIL.



No they dont. They are in fact nothing like RECHARGABLE lithium technology.


A lithium cell WILL produce 3V regardless of it´s type. A rechargeable
lithium battery or a non rechargeable one will have the same voltage
output. That´s what the chemistry produces, and you can´t reduce that
voltage chemically, so they must have some built in electronic method
to reduce the voltage to the standard 1.5 V a AA cell should produce.

You need to learn to do your research before you make statements you
cannot support. You've proven yourself to be a blowhard.

If that is true, then it´s possible that in several
years that circuit will be designed to allow a
safe recharging of a lithium AA or AAA battery.

Its obvious technically possible right now given that cellphones
and ipods etc can obviously charge them fine now, and with
cellphones particularly can handle all of NiMH, NiCad and Lion etc.

The problem is that if they are in AA or AAA format, there
is nothing to stop an individual putting them in an inappropriate
charger and ending up with a massive legal liablity problem.

Except the Lithium E2, which is a non-rechargeable battery
(officially) The PTC device prevents them from being charged too hard
or overheated if inadvertently put into a charger.. They WILL accept a
charge - I don't know how much capacity the recharged cell has yet as
I have not tested it. I charged it with a regulated power supply
current limited to 350ma and voltage limitted to 1.65. I need to crank
both current and voltage up a bit to get a full charge - the battery
was at .7 volts when I pulled it out of the clock and after two hours
it is at 1.2 and has held that voltage for 3 days. I'm going to rig up
a proper holder, then put the battery outside on the charger for 5
hours at 500ma and 2.35 volts and see what happens. If it blows up
it'll make a little crater in the snow but I'm convinced the
protection of the PTC device will not allow that to happen.


As I stated previously, if you move the charging circuit to the cell
itself, the problem of the charger dissapears completely.

Not with a standard battery format they cant, because that
would inevitably see some put them on inappropriate chargers
that would produce spectacular results when they did that.

The technollogy exists, and in fact it´s in use actually.

No it isnt with STANDARD BATTERY FORMATS.

Take this cordless phone, for instance,

http://gigaset.siemens.com/shc/0,193... html#content

It´s designed to work with standard AAA rechargeable batteries.

So is mine. Pity it doesnt accept Lithium rechargable AAA batterys.


I don´t care it it cannot take Lithium or Plutonium batteries. The
point here is that the phone is designed to take a standard
rechargeable battery which will be available forever, and not a
proprietary battery which surely will be non available when the need to
replace it arises.

Also I own a Siemens C4000 cordless phone and it works with
standard AA rechargeable batteries. It can take NiCd or NiMh batteries.

So does my Panasonic, and I bought it for that reason.

It will not however accept lithium rechargable batterys.

Both of my current cellphones, Nokias, will accept all of NiMH,
NiCad and Lion batterys, but they arent AA or AAA format
because there is too much risk with that approach of someone
trying to charge the Lion batterys with a separate charger that
doesnt know how to charge Lion batterys.


If you move the charging circuit to the battery pack (like laptops
battery packs do), you don´t have to worry about that.

So, *if* the manufacturer wants to develop a product
using standard rechageable batteries, *it can do it*.

Nope, because there is no way to stop someone putting
it in a charger that knows nothing about Lion charging.


I said "standard rechargeable batteries", not LiOn. What part of that
didn´t you understood?

And a "new standard" could easilly be established for rechargeable
Lithiums as well. With or without internal protection.


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