clare at snyder.on.ca wrote
Rod Speed wrote
lsmartino wrote
Rod Speed wrote
Thatīs why the manufacturer puts the charging circuit *inside*
the cellphone or the laptop, to avoid charging problems.
Yes, and why you dont see rechargeable lithium AA and AAA batterys,
because some fool will inevitably put them in an inappropriate
charger and they can go bang very spectacularly indeed.
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.
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.
There is NO ELECTRICAL ENGINEERING required.
Sure, the problem is just a basic mechanical/size one.
Make a "new standard" battery that will only fit the proper
charger or device provided with internal charger circuit.
Thats what they have already done with ipods
and electric toothbrushes and cellphones.
Put contacts on it that mate with contacts in the devices.
Thats what has already been done with cellphones.
Absolutely no reason it cannot be done.
Its not feasible to put the charging circuit
INSIDE THE CURRENT IPOD BATTERY.
THATS what was being discussed there.
No really that practical with electric toothbrushes either.
It can be the battery currently used in an application, with contacts added.
Not with an ipod with the charger inside THAT battery. Its too small.
Makes it field replaceable
The ipod battery is field replaceable now.
- doesn't even matter if there is an external charger
available (isn't for half the cell phone batteries either)
There always is for the cellphone and battery combined.
And for the ipod too. With it even just USB is fine.
Thus the charger used to recharge the battery becames
inmaterial because any proper voltage source will suffice.
The problem aint the voltage source.
In fact, since lithium cells produce 3V, and a AA battery
shouldnīt produce more than 1.5V, I suspect that these
lithium cells have some form of voltage regulating circuit inside.
No they dont. They are in fact nothing like RECHARGABLE lithium technology.
If that is true, then itīs 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.
Also, the IPOD battery is a lithium rechargeable one, so a
lithium battery charging circuit can be made as small as needed.
Yes, but we were discussing why the battery
cant be a STANDARD AA OR AAA FORMAT.
Put simply: if the manufacturer *wants* to design a product with
batteries that can be replaced or recharged the manufacturer
*can* do it.
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 itīs 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
Itīs designed to work with standard AAA rechargeable batteries.
So is mine. Pity it doesnt accept Lithium rechargable AAA batterys.
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.
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.
Even there are different chemistries available,
so if an applicattion works best with a NiMh
battery, or a NiCad one, that battery can be used.
Pity about the problem with putting a lithium battery in a charger
thats designed to charge NiMh and NiCad standard format betterys.