Natural Science Forum / Chemistry / Electrochemistry / September 2007

could anybody explain the difference between polarization resistance and
contact resistance of an electode in electolytic circuit ?
thanks
best regards

Had the bright idea of using alkaline ferrate as a cathode material only to
find it's been done already.  Has anybody out there actually seen or used a
super-iron cell?  Does it provide 300-400 W-hr/kg at 1.75V, or is that only
theoretical?

After years of college electronics and more years in the field, I
discovered Duracell batteries (type A etc) have a charge gauge on the
side. How does this work? Are microchips, zeiner diodes , a/d
converters involved or what??

Very often I've read that "1.2 volt" NiMH cells won't work in devices
that were designed for "1.5 volt" alkaline cells because their voltage
is too low. Having tired of repetitively explaining why this is a myth,
I put together an essay on the topic. You'll find it at

I am trying to find a battery equivalent to power a small bullet
camera. The camera is suppose to require at most 100mA of 12V DC. It
works fine when I use the transformer plugged into the A/C supply but
I want to power it off the smallest batteries that I can so it is more

Hi Newsgroup.
Anyone know how to recharge non-rechargeable batteries? I believe it
is possible.
Andrew Lin

    I tried searching google and I didn't find anything exept
advertising for sub-c cells.  Is it a different chemistry?  Are they
the same form factor as other cells like AA, AAA, C, D?  The only
thing I can seem to find about them is that they can provide lots of

I have come up with an idea for an inexpensive, light weight, high
capacity battery for a small trolling motor to be used in a small
canoe.  But can I place 10 batteries in series in parallel with
another 10 batteries in series?  This works in concept but I have