Natural Science Forum / Chemistry / Electrochemistry / April 2005

I found myself a discarded electric scooter.  Inside were two nicely sulfated
12 ah batteries.  I'm going to keep them connected to a charger in a
"controlled overcharge" mode for several days and see what happens.

When building a li-ion pack, how important is it to confirm equal voltages
for each cell in the pack? Will unequal cell voltages reduce the maximum
performance of the pack? If so, will this reduce given several
charge/discharge cycles?

I was reading this recent article on atom clusters, aka 'Superatoms'
http://www.newscientist.com/channel/fundamentals/mg18624951.800
Could these be used for new fuel chemistry or battery chemistry?
Suppose SuperAtoms of Li-ion or Al-ion were used for fuels or

   I am using a max712 charger for 2100 mah nimh cells. Our area has
frequent power failures. What will be effect of such power failures during
charging? I guess that the backup timer may no more be dependable and that
if the charge termination works fine, there should be no ...

I think I remember hearing that NiMH batteries do not keep charge for
6 months at a time like alkalines, or maybe they have improved them.
Is there a good type of rechargeable battery to get for opt. mice?
Are the alkaline renewals by rayovac no longer sold?

Sorry for asking a fundamental question but can you buy rechargeable 1.5v AA
batteries.  All seem to be 1.2v. This cause problem with some of my
equipment.
Cheers

   I recently bought four 2100mah Sanyo ni-mh cells for use in a
flashlight. When i tried a 5.5V, 1A bulb, the voltage dropped to around
3.6V. With another bulb taking 0.5A, the voltage was around 4.1V. Is this
normal? With nicd cells, there was not much drop. I thought nimh and ...

i hope some one can please help me with a BIG!! problem i am
having...
I have Recently started making some Lead Dioxide anodes for a
electrochemical cell. the anodes are aprox 36 mm diameter 2 mm thick

What happens when you snap two 9-volt batteries together using clips so
that plus goes to minus and vice versa?

I'm adapting an older portable air-band scanner receiver and a cheap FM
transmitter to provide local airport radio chatter on an FM frequency so
that people sitting in the parking lot of our airport can tune in on their
car radios and listen to the airplanes.  This scanner forgets ...

Charging NIMH in warm areas:
Apwcifically Sanyo HR-AUC cells.
They limit the high rate charge temperature to 40C.
What is this limit based on?

Does anyone know of a reference to a detailed atomic description on the
anodizing of aluminum.
Is the thickness controlled by the applied voltage?
I desire a aluminum oxide with silicon in with a controlled thickness.

       I am designing a multi-level factorial design to analysis the
electrochemical effect AC has on printed circuit board contamination.
Ultimately the overall reliability of the product.  E.g. do we get
dendrites, complex oxides or corrosive products.    I have so good ideas ...

 Does anyone know of any possible sources for NI200 nickel in the form of
either battery tabs, sheets or rolls? I'd prefer a UK source if at all
possible.
 It seems McMaster-Carr sell NI200 as their order code "9707K33" but I

I am a total newbie to the ng -- reading u often and from much time.
I'd like to point all you over this site:
http://www.unibatt.com/products.htm
They claim ultra energy density for their batteries --