Natural Science Forum / Chemistry / Electrochemistry / September 2005

I'm kinda learning as I go... at work, we bought about 80 NiMH batteries
for some handheld equipment (GPS units, etc.). These are name brand, decent
mh.
We've used them about a dozen times, and now we are having trouble with

Where can I buy 105 AH deep-cycle flooded lead-acid batteries without
acid?  I want to store them until needed (which might not be for
several years), at which time I would add the acid.
Ken C

I am interested in background, theory and refences to ion transport
under high fields in electrolytes and solids. Specifically why there is
nonohmic behavior. Lars Onsager mentions some references in his nobel
speech, but these are really old (and hence difficult to acquire). I

    Greetings. I've a power wheelchair driven by two 12V gel batteries.
I use it all day, every day. I get very good range at speed out of it and
testing has shown the batteries will 'last' (i.e., give good performance)
for at least three years (of course, the range will drop off).

I'm looking to buy a new nimh battery charger (actually I'd like one that
would do discharge-charge cycles).
I've noticed that a lot of places now had NexxTech chargers & batteries
(and a whole bunch of other stuff). I would like to know if NexxTech's

My NiCad batteries were pretty much dead, so I decided I would get modern
and buy Nimh batteries. For anybody knowing nothing about batteries, or
even electricity, shopping for a charger is really brain numbing. Some
chargers come with 2500 mah batteries, some other don't utter ...

I read from previous papers that direct electron transfer is possible
when laccase is adsorbed onto edge plane pyrolytic graphite electrode.
I recently bought a HOPGE electrode from PINE instrunment but I did not
observe any catalytic current in the presence of oxygen when laccase ...

I have just bought four 110Ah Varta Semi-Traction batteries to use as a
battery bank for an inverter.  The battery will spend 99.9 percent of it's
time sitting on float charge, and only used in power cut situations.
Any opinions on best voltage to float the battery at?  My three ...

Some Li-Ion  laptop batteries are getting cheap enough to consider for
general use.  See, e.g., eBay item no. 6802321789.
Is there a common method to charge these?
I have tried in the past to charge Li-Ion laptop batteries using a

I have one of those automotive jump-start devices, consisting of a 12V 7.2AH
sealed cell in a plastic case with cigarette lighter cord for connecting
to the other car, and a 12VDC output for powering accessories. It comes
with a small wall wart for recharging, whose output is 15 VDC ...

I have an application, hand bearing compass, that calls for 2 AAA
"non-magnetic" batteries. The instructions call for Ray-O-Vac # 400 or
Eveready #912. Both of these are no longer produced.
Alkaline and heavy-duty types throw the compass well off.

I have a rechargeable camping type lantern.  The box claims the lamp is
9 watts and will burn for 8-10 hours on a single charge.  The battery
is 6v and 4 Ah SLA (Sealed Lead Acid).  If the lamp is also 6v, then it
is drawing 1.5 amps, so on a 4 Ah battery I would not expect much ...

I have a question regarding use of the "right" impedance analyzer to
perform electrochemical impedance spectroscopy.
Is there a difference between using say an Agilent 4192A (or an LCR
meter) to make impedance measurements across an electrochemical cell and

I'm a very occasional picture-taker, so my digital camera often sits for
a month or more without being used. There are two NiMH AA cells in the
camera, and I keep two more pairs in the case. Before going on a trip or
doing something else that's likely to involve a lot of ...