Natural Science Forum / Chemistry / Electrochemistry / December 2003

*******************************************************************************
                    Frequently Asked Questions, Part 1 of 3
                         SCI.CHEM.ELECTROCHEM/ELETQM-L
                          Revision date: December 11, 2003.

I have an unusual situation.
Three battery packs failed here, in a very unusual way.
I'm looking for any ideas on what could have caused this.
The pack construction is unremarkable, shrink-wrapped cells, Suppo 2100MAh

I can't find any serious performance data on 'lead-vitriol' batteries,
having only seen them offered here:
http://www.symmetryco.com/battery.htm
A quick Google shows that lead vitriol is  PbS04, AKA 'Anglesite'.

HI,
I assembled 9 1600mah NIMH into a pack.  I charge the pack at 13 volts
at 100ma for 2 days then put into my bike light circuit that draws
300ma.

I have a question reguarding the use of a desktop pH meter, The meter
I am using comes with a BNC cap that shorts out the input to the pH
meter, but I have to remove the cap to use a pH electrode to make
measurements, what is the cap used for? and when would I use it?

Hello battery experts,
I would like to replace the NiCd cells in my cordless drill's battery pack
with NiMH cells. I have a fast (~ 1hr) charger that came with the drill. It
seems that the charger uses a temperature probe to determine when to stop

I did some rough and approximate measurements of the temperature
characteristics and charging performance of a half dozen commercial
chargers for AA NiMH cells.
Figured the folks here might find the data interesting.

I found this guide, which shows how you easily can make a solor cell:
http://www.scitoys.com/scitoys/scitoys/echem/echem2.html
Could somone show me the reactions which creates the cuprous oxide? First
cupric oxide, then cuprous oxide...

I'd like a battery to supply a low power clock chip, say 10uA @ 3V for
1 month, at temperatures from say 0 to 200C, but not ncessarily in a
compact package.  In other words, the world's worst battery in every
respect except temperature range.

I have a battery charger that requires DC12V, but it's adapter is UK style,
so I can't use it's original adapter.
The original adapter says it outputs at DC12V ~ 1500mAh.
Right now I'm using an universal adapter that outputs at DC12V, but ~

Could someone here please tell me how may watts of electricity are
required to electrolyze one liter of hydrogen from water at STP?

When you charge a battery with a 14V DC source.
While the internal resisitance is 0.01ohm.
The current going through is 1400A?!!

In the past, I have used impedance spectroscopy for understanding
electrochemical systems with ionic charge carrier transport (e.g.
quantifying/separating grain versus bulk oxygen ionic conductivity
in solid state ion conductors.) Can the same technique be used to

I am just wondering usually how "full"(say the max capacity is 100%) a
battery is it capable to start a car?
I was reading a charger manual which told me if my battery is 50% full, I
still need to charge it for 4 hours.

Can I say that rectifiers are a type of transformers?
Or transormers refer to AC-AC only?