Natural Science Forum / Chemistry / Electrochemistry / February 2004

Hello and regards from Ireland! I wonder if someone could help me. I
have been assigned a project to prepare low conductivity standards,
like 5uS/cm and 10uS/cm and high conductivity standards like 5000uS/cm
and the like. Unfortunately I cannot find any information about how to

I am looking for a paper that would make an estimate of what values for
the exponent of the CPE are still acceptable if one wants to substitute an
R(RC) circuit with an R(RQ). I know all the experimentalists just use a
CPE as long as the results support what one wants to see. ...

I'm a cross-over from the sci.electronics.basics board, and have a
question that I hope someone here can provide me with an answer.  I've
been developing a circuit and needed to make several circuit boards.
The process is the positive photoresistive type, and requires the

Hello Group
First of all my apologies for an off-topic post ... but it seems that you
will be the most knowledgeable resource.
I've got a battery marked: Eveready / 4,5V / 3R25 / AD28 / 0%

Survey:
1. Who want battery simulation or modelling software?
2. What do you want from battery simulation?
3. How much would you pay?

I have a old NEC laptop Versa 2780 MT (6-7 years) how can I find a battery
for it. Description: NEC Li-ion battery pack, # OP-570-68001, 14.4 V, 2600
mAh.
Armand

I am wondering if anyone has a circuit design for a simple Low Voltage
"Cut-Out" for 12 or 6 Volt Sealed Lead Acid Batteries.  What I would
like to do is connect a small circuit to a sealed lead-acid battery
that will not allow you to drain the battery below a certain, safe

In a short quest to discover the best way of maintaining, recovering
and using gel acid batteries I have come across a manufacturers
recommendation that banks of gel acid batteries be "Discharged, and
recharged as a set, fully for several deep cycles" in order to

1. My question
There are two kinds of oxygen ions.
Group A: oxygen ions activated by thermal energy
Group B: any other oxygen ions except Group A

Can anyone tell me the practical difference between a Lithium coin
cell with the prefix "BR" and one with the prefix "CR"?
I see that the Panasonic BR2325 is an LiCF (Lithium
Carbon-monoflouride) and the Renata CR2325 is an LiMnO2 (Lithium

Happened to be at the local Fry's and happened to see this 4 hour quick
charger for AAs and AAAs with 4 1900 mAH AAs on sale for $9.99 through
tomorrow. Its a X1 Charge Pro model CHB-7NSS-4B. The pricing is pretty good,
but I've not seen it sold anywhere else or any reviews on it.

Got a recently 'death bed' Li-ion battery for my
notebook (neglected it for months and now it does
not hold a charge).
Is there a way to 'revitalize' a Li-ion, such as

Good evening,
I would like to know the chemestry of see water activated battery.
How does it work?
How long can be the life before immersion?

Can anyone tell me how I can acquire a copy of Dr. Bernard A. Boukamp
Equivalent Circuit Program.  I have tried searching the internet, there are
plenty of ref. but not mention of where I can get the program.
Cheers

Can someone point me to some simple NiMh battery charger homebrew
projects/schematics.  I know I've got enough junk in the garage to
build one.  When I do a search on google all I find all commercial
ready to go.  And yes, I know I should just buy one.  If I don't try